While there are a mix of things here, most of the stuff
were written from Kernel developer's PoV. So, add them to
the driver-api book.
A follow up for this patch would be to move documents from
there that are specific to sysadmins, adding them to the
admin-guide.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The variable rv is assigned with a value that is never read and
it is re-assigned a new value on the next statement. The
assignment is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Clean up the throttle implementation by dropping the redundant
throttle_req flag which was a remnant from back when USB serial had only
a single read URB, something which was later carried over to cdc-acm.
Also convert the throttled flag to an atomic bit flag.
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix two long-standing bugs which could potentially lead to memory
corruption or leave the port throttled until it is reopened (on weakly
ordered systems), respectively, when read-URB completion races with
unthrottle().
First, the URB must not be marked as free before processing is complete
to prevent it from being submitted by unthrottle() on another CPU.
CPU 1 CPU 2
================ ================
complete() unthrottle()
process_urb();
smp_mb__before_atomic();
set_bit(i, free); if (test_and_clear_bit(i, free))
submit_urb();
Second, the URB must be marked as free before checking the throttled
flag to prevent unthrottle() on another CPU from failing to observe that
the URB needs to be submitted if complete() sees that the throttled flag
is set.
CPU 1 CPU 2
================ ================
complete() unthrottle()
set_bit(i, free); throttled = 0;
smp_mb__after_atomic(); smp_mb();
if (throttled) if (test_and_clear_bit(i, free))
return; submit_urb();
Note that test_and_clear_bit() only implies barriers when the test is
successful. To handle the case where the URB is still in use an explicit
barrier needs to be added to unthrottle() for the second race condition.
Also note that the first race was fixed by 36e59e0d70 ("cdc-acm: fix
race between callback and unthrottle") back in 2015, but the bug was
reintroduced a year later.
Fixes: 1aba579f3c ("cdc-acm: handle read pipe errors")
Fixes: 088c64f812 ("USB: cdc-acm: re-write read processing")
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the kernel is compiled with preemption enabled, the URB completion
handler can run in parallel with the work responsible for waking up the
tty layer. If the URB handler sets the EVENT_TTY_WAKEUP bit during the
call to tty_port_tty_wakeup() to signal that there is room for additional
input, it will be cleared at the end of this call. As a result, TX traffic
on the upper layer will be blocked.
This can be seen with a kernel configured with CONFIG_PREEMPT, and a fast
modem connected with PPP running over a USB CDC-ACM port.
Use test_and_clear_bit() instead, which ensures that each wakeup requested
by the URB completion code will trigger a call to tty_port_tty_wakeup().
Fixes: 1aba579f3c cdc-acm: handle read pipe errors
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'rv' is the correct return value, pass it upstream instead of 0
Fixes: 17d80d562f ("USB: autosuspend for cdc-wdm")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a few remaining drivers/usb/ files that do not have SPDX
identifiers in them, all of these are either Kconfig or Makefiles. Add
the correct GPL-2.0 identifier to them to make scanning tools happy.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Telit 3G Intel based modems require zero packet to be sent if
out data size is equal to the endpoint max packet size.
Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mediatek Preloader is a proprietary embedded boot loader for loading
Little Kernel and Linux into device DRAM.
This boot loader also handle firmware update. Mediatek Preloader will be
enumerated as a virtual COM port when the device is connected to Windows
or Linux OS via CDC-ACM class driver. When the USB enumeration has been
done, Mediatek Preloader will send out handshake command "READY" to PC
actively instead of waiting command from the download tool.
Since Linux 4.12, the commit "tty: reset termios state on device
registration" (93857edd98) causes Mediatek
Preloader receiving some abnoraml command like "READYXX" as it sent.
This will be recognized as an incorrect response. The behavior change
also causes the download handshake fail. This change only affects
subsequent connects if the reconnected device happens to get the same minor
number.
By disabling the ECHO termios flag could avoid this problem. However, it
cannot be done by user space configuration when download tool open
/dev/ttyACM0. This is because the device running Mediatek Preloader will
send handshake command "READY" immediately once the CDC-ACM driver is
ready.
This patch wants to fix above problem by introducing "DISABLE_ECHO"
property in driver_info. When Mediatek Preloader is connected, the
CDC-ACM driver could disable ECHO flag in termios to avoid the problem.
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Cc: stable@vger.kernel.org
Reviewed-by: Johan Hovold <johan@kernel.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The cdc-acm kernel module currently does not support the Hiro (Conexant)
H05228 USB modem. The patch below adds the device specific information:
idVendor 0x0572
idProduct 0x1349
Signed-off-by: Maarten Jacobs <maarten256@outlook.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big USB/PHY driver patches for 4.20-rc1
Lots of USB changes in here, primarily in these areas:
- typec updates and new drivers
- new PHY drivers
- dwc2 driver updates and additions (this old core keeps getting added
to new devices.)
- usbtmc major update based on the industry group coming together and
working to add new features and performance to the driver.
- USB gadget additions for new features
- USB gadget configfs updates
- chipidea driver updates
- other USB gadget updates
- USB serial driver updates
- renesas driver updates
- xhci driver updates
- other tiny USB driver updates
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCW9LlHw8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ymnvwCffYmMWyMG9zSOw1oSzFPl7TVN1hYAoMyJqzLg
umyLwWxC9ZWWkrpc3iD8
=ux+Y
-----END PGP SIGNATURE-----
Merge tag 'usb-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB/PHY updates from Greg KH:
"Here is the big USB/PHY driver patches for 4.20-rc1
Lots of USB changes in here, primarily in these areas:
- typec updates and new drivers
- new PHY drivers
- dwc2 driver updates and additions (this old core keeps getting
added to new devices.)
- usbtmc major update based on the industry group coming together and
working to add new features and performance to the driver.
- USB gadget additions for new features
- USB gadget configfs updates
- chipidea driver updates
- other USB gadget updates
- USB serial driver updates
- renesas driver updates
- xhci driver updates
- other tiny USB driver updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'usb-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (229 commits)
usb: phy: ab8500: silence some uninitialized variable warnings
usb: xhci: tegra: Add genpd support
usb: xhci: tegra: Power-off power-domains on removal
usbip:vudc: BUG kmalloc-2048 (Not tainted): Poison overwritten
usbip: tools: fix atoi() on non-null terminated string
USB: misc: appledisplay: fix backlight update_status return code
phy: phy-pxa-usb: add a new driver
usb: host: add DT bindings for faraday fotg2
usb: host: ohci-at91: fix request of irq for optional gpio
usb/early: remove set but not used variable 'remain_length'
usb: typec: Fix copy/paste on typec_set_vconn_role() kerneldoc
usb: typec: tcpm: Report back negotiated PPS voltage and current
USB: core: remove set but not used variable 'udev'
usb: core: fix memory leak on port_dev_path allocation
USB: net2280: Remove ->disconnect() callback from net2280_pullup()
usb: dwc2: disable power_down on rockchip devices
usb: gadget: udc: renesas_usb3: add support for r8a77990
dt-bindings: usb: renesas_usb3: add bindings for r8a77990
usb: gadget: udc: renesas_usb3: Add r8a774a1 support
USB: serial: cypress_m8: remove set but not used variable 'iflag'
...
Pull tty ioctl updates from Al Viro:
"This is the compat_ioctl work related to tty ioctls.
Quite a bit of dead code taken out, all tty-related stuff gone from
fs/compat_ioctl.c. A bunch of compat bugs fixed - some still remain,
but all more or less generic tty-related ioctls should be covered
(remaining issues are in things like driver-private ioctls in a pcmcia
serial card driver not getting properly handled in 32bit processes on
64bit host, etc)"
* 'work.tty-ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (53 commits)
kill TIOCSERGSTRUCT
change semantics of ldisc ->compat_ioctl()
kill TIOCSER[SG]WILD
synclink_gt(): fix compat_ioctl()
pty: fix compat ioctls
compat_ioctl - kill keyboard ioctl handling
gigaset: add ->compat_ioctl()
vt_compat_ioctl(): clean up, use compat_ptr() properly
gigaset: don't try to printk userland buffer contents
dgnc: don't bother with (empty) stub for TCXONC
dgnc: leave TIOC[GS]SOFTCAR to ldisc
remove fallback to drivers for TIOCGICOUNT
dgnc: break-related ioctls won't reach ->ioctl()
kill the rest of tty COMPAT_IOCTL() entries
dgnc: TIOCM... won't reach ->ioctl()
isdn_tty: TCSBRK{,P} won't reach ->ioctl()
kill capinc_tty_ioctl()
take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()
synclink: reduce pointless checks in ->ioctl()
complete ->[sg]et_serial() switchover
...
The usb standard ("Universal Serial Bus Class Definitions for Communication
Devices") distiguishes between "consistent signals" (DSR, DCD), and
"irregular signals" (break, ring, parity error, framing error, overrun).
The bits of "irregular signals" are set, if this error/event occurred on
the device side and are immeadeatly unset, if the serial state notification
was sent.
Like other drivers of real serial ports do, just the occurence of those
events should be counted in serial_icounter_struct (but no 1->0
transitions).
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Resetting the write index of the notification buffer on urb unlink (e.g.
closing a cdc-acm device from userspace) may lead to wrong interpretation
of further received notifications, in case the index is not 0 when urb
unlink happens (i.e. when parts of a notification already have been
transferred). On the device side there is no "reset" of the notification
transimission and thus we would get out of sync with the device.
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a device splits up a control message and a reset() happens
between the parts, the message is lost and already recieved parts
must be dropped.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Fixes: 1aba579f3c ("cdc-acm: handle read pipe errors")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the ACM TTY port is disconnected, the URBs it uses must be killed, and
then the buffers must be freed. Unfortunately a previous refactor removed
the code freeing the buffers because it looked extremely similar to the
code killing the URBs.
As a result, there were many new leaks for each plug/unplug cycle of a
CDC-ACM device, that were detected by kmemleak.
Restore the missing code, and the memory leak is removed.
Fixes: ba8c931ded ("cdc-acm: refactor killing urbs")
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix uninitialized symbol 'actual' in function
usbtmc_ioctl_abort_bulk_in_tag().
When symbol 'actual' is not initialized and usb_bulk_msg() fails,
the subsequent kernel debug message shows invalid data.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Fixes: cbe743f133 ("usb: usbtmc: Fix ioctl USBTMC_IOCTL_ABORT_BULK_IN")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix uninitialized symbol 'actual' in function usbtmc_ioctl_clear.
When symbol 'actual' is not initialized and usb_bulk_msg() fails,
the subsequent kernel debug message shows a random value.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Fixes: dfee02ac4b ("usb: usbtmc: Fix ioctl USBTMC_IOCTL_CLEAR")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix uninitialized symbol 'actual' in function usbtmc_read.
When symbol 'actual' is not initialized and usb_bulk_msg() fails,
the subsequent kernel debug message shows a random value.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Fixes: d7604ff0dc ("usb: usbtmc: Optimize usbtmc_read")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kernel memory is allocated twice in new function
usbtmc_ioctl_request and creates a memory leak.
This fix removes the superfluous kmalloc().
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Fixes: 658f24f452 ("usb: usbtmc: Add ioctl for generic requests on control")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As all the properties of the usbtmc driver can now be
controlled on a per file descriptor basis by ioctl functions
the sysfs interface is of limited use.
We are not aware about applications that are using the sysfs
parameter TermChar, TermCharEnabled or auto_abort.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add ioctl USBTMC_IOCTL_API_VERSION to get current API version
of usbtmc driver.
This is to allow an instrument library to determine whether
the driver API is compatible with the implementation.
The API may change in future versions. Therefore the macro
USBTMC_API_VERSION should be incremented when changing tmc.h
with new flags, ioctls or when changing a significant behavior
of the driver.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use common timeout macro USB_CTRL_GET_TIMEOUT (=5s) for all
usb_control_msg() function calls.
The macro USBTMC_TIMEOUT should only be used as default value for
Bulk IN/OUT transfers.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add parameter 'tag' to function usbtmc_ioctl_abort_bulk_out_tag()
for future versions.
Use USBTMC_BUFSIZE (4k) instead of USBTMC_SIZE_IOBUFFER (2k).
Using USBTMC_SIZE_IOBUFFER is deprecated.
Insert a sleep of 50 ms between subsequent
CHECK_ABORT_BULK_OUT_STATUS control requests to avoid stressing
the instrument with repeated requests.
Use common macro USB_CTRL_GET_TIMEOUT instead of USBTMC_TIMEOUT.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add parameter 'tag' to function usbtmc_ioctl_abort_bulk_in_tag()
for future versions.
Remove calculation of max_size (=wMaxPacketSize) and wrong
condition (actual == max_size) in while loop. An abort operation
should always flush the complete Bulk-IN until a short packet is
received.
Return error code ENOMSG when transfer (specified by given tag)
is not in progress and device returns code
USBTMC_STATUS_TRANSFER_NOT_IN_PROGRESS.
Use USBTMC_BUFSIZE (4k) instead of USBTMC_SIZE_IOBUFFER (2k).
Using USBTMC_SIZE_IOBUFFER is deprecated.
Use common macro USB_CTRL_GET_TIMEOUT instead of USBTMC_TIMEOUT.
Check only bit 0 (field bmAbortBulkIn) of the
CHECK_ABORT_BULK_IN_STATUS response, since other bits are reserved
and can change in future versions.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove calculation of max_size (=wMaxPacketSize) and wrong
condition (actual == max_size) in while loop. A device clear
should always flush the complete Bulk-IN FIFO.
Insert a sleep of 50 ms between subsequent CHECK_CLEAR_STATUS
control requests to avoid stressing the instrument with
repeated requests.
Some instruments need time to cleanup internal I/O buffers.
Polling and nonbraked requests slow down the response time of
devices.
Use USBTMC_BUFSIZE (4k) instead of USBTMC_SIZE_IOBUFFER (2k).
Using USBTMC_SIZE_IOBUFFER is deprecated.
Check only bit 0 (field bmClear) of the CHECK_CLEAR_STATUS
response, since other bits are reserved and can change in
future versions.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use new usbtmc_generic_read function to maximize bandwidth
during long data transfer. Also fix reading of zero length
packet (ZLP) or trailing short packet.
The maximum input transfer size is limited to INT_MAX (=2GB).
Also remove redundant return in send_request_dev_dep_msg_in().
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use new usbtmc_generic_write function to maximize bandwidth
during long data transfer.
The maximum output transfer size is limited to INT_MAX (=2GB).
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add ioctl USBTMC_IOCTL_AUTO_ABORT to configure auto_abort for
each specific file handle.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
add ioctl USBTMC_IOCTL_MSG_IN_ATTR that returns the specific
bmTransferAttributes field of the last DEV_DEP_MSG_IN Bulk-IN
header. This header is received by the read() function. The
meaning of the (u8) bitmap bmTransferAttributes is:
Bit 0 = EOM flag is set when the last transfer of a USBTMC
message is received.
Bit 1 = is set when the last byte is a termchar (e.g. '\n').
Note that this bit is always zero when the device does not support
the termchar feature or when termchar detection is not enabled
(see ioctl USBTMC_IOCTL_CONFIG_TERMCHAR).
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Wait until an SRQ (service request) is received on the interrupt pipe
or until the given period of time is expired. In contrast to the
poll() function this ioctl does not return when other (a)synchronous
I/O operations fail with EPOLLERR.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Submitted urbs are not allowed when system is suspended.
Thus the submitted urb waiting at interrupt pipe is killed
during suspend callback and submitted again when system resumes.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ioctl USBTMC_IOCTL_CLEANUP_IO kills all submitted urbs to OUT
and IN bulk, and clears all received data from IN bulk. Internal
transfer counters and error states are reset.
An application should use this ioctl after an asnychronous transfer
was canceled and/or error handling has finished.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ioctl USBTMC_IOCTL_CANCEL_IO stops and kills all flying urbs of
last USBTMC_IOCTL_READ and USBTMC_IOCTL_WRITE function calls.
A subsequent call to USBTMC_IOCTL_READ or
USBTMC_IOCTL_WRITE_RESULT returns -ECANCELED with
information about current transferred data.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USBTMC_IOCTL_READ call provides for generic synchronous and
asynchronous reads on bulk IN to implement vendor specific library
routines.
Depending on transfer_size the function submits one or more urbs (up
to 16) each with a size of up to 4kB.
The flag USBTMC_FLAG_IGNORE_TRAILER can be used when the transmission
size is already known. Then the function does not truncate the
transfer_size to a multiple of 4 kB, but does reserve extra space
to receive the final short or zero length packet. Note that the
instrument is allowed to send up to wMaxPacketSize - 1 bytes at the
end of a message to avoid sending a zero length packet.
With flag USBTMC_FLAG_ASYNC the ioctl is non blocking. When no
received data is available, the read function submits as many urbs as
needed to receive transfer_size bytes. However the number of flying
urbs (=4kB) is limited to 16 even with subsequent calls of this ioctl.
Returns -EAGAIN when non blocking and no data is received.
Signals EPOLLIN | EPOLLRDNORM when asynchronous urbs are ready to
be read.
In non blocking mode the usbtmc_message.message pointer may be NULL
and the ioctl just submits urbs to initiate receiving data. However if
data is already available due to a previous non blocking call the ioctl
will return -EINVAL when the message pointer is NULL.
This ioctl does not support compatibility for 32 bit
applications running on 64 bit systems. However all other
convenient ioctls of the USBTMC driver can still be used in 32
bit applications as well. Note that 32 bit applications running
on 32 bit target systems are not affected by this limitation.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ioctl USBTMC_IOCTL_WRITE_RESULT copies current out_transfer_size
to given __u32 pointer and returns current out_status of the last
(asnynchronous) USBTMC_IOCTL_WRITE call.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The new ioctl USBTMC_IOCTL_WRITE sends a generic message to bulk OUT.
This ioctl is used for vendor specific or asynchronous I/O as well.
The message is split into chunks of 4k (page size).
Message size is aligned to 32 bit boundaries.
With flag USBTMC_FLAG_ASYNC the ioctl is non blocking.
With flag USBTMC_FLAG_APPEND additional urbs are queued and
out_status/out_transfer_size is not reset. EPOLLOUT | EPOLLWRNORM
is signaled when all submitted urbs are completed.
Flush flying urbs when file handle is closed or device is
suspended or reset.
This ioctl does not support compatibility for 32 bit
applications running on 64 bit systems. However all other
convenient ioctls of the USBTMC driver can still be used in 32
bit applications as well. Note that 32 bit applications running
on 32 bit target systems are not affected by this limitation.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add USBTMC_IOCTL_CTRL_REQUEST to send arbitrary requests on the
control pipe. Used by specific applications of IVI Foundation,
Inc. to implement VISA API functions: viUsbControlIn/Out.
The maximum length of control request is set to 4k.
This ioctl does not support compatibility for 32 bit
applications running on 64 bit systems. However all other
convenient ioctls of the USBTMC driver can still be used in 32
bit applications as well. Note that 32 bit applications running
on 32 bit target systems are not affected by this limitation.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 6e22e3af7b.
The bug the patch describes to, has been already fixed in commit
2df6948428 ("USB: cdc-wdm: don't enable interrupts in USB-giveback")
so need to this, revert it.
Fixes: 6e22e3af7b ("usb: cdc-wdm: Fix a sleep-in-atomic-context bug in service_outstanding_interrupt()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit a81cf9799a.
The patch causes a regression, which I cannot find the reason for.
So let's revert for now, as a revert hurts only performance.
Original report:
I was trying to resolve the problem with Oliver but we don't get any conclusion
for 5 months, so I am now sending this to mail list and cdc_acm authors.
I am using simple request-response protocol to obtain the boiller parameters
in constant intervals.
A simple one transaction is:
1. opening the /dev/ttyACM0
2. sending the following 10-bytes request to the device:
unsigned char req[] = {0x02, 0xfe, 0x01, 0x05, 0x08, 0x02, 0x01, 0x69, 0xab, 0x03};
3. reading response (frame of 74 bytes length).
4. closing the descriptor
I am doing this transaction with 5 seconds intervals.
Before the bad commit everything was working correctly: I've got a requests and
a responses in a timely manner.
After the bad commit more time I am using the kernel module, more problems I have.
The graph [2] is showing the problem.
As you can see after module load all seems fine but after about 30 minutes I've got
a plenty of EAGAINs when doing read()'s and trying to read back the data.
When I rmmod and insmod the cdc_acm module again, then the situation is starting
over again: running ok shortly after load, and more time it is running, more EAGAINs
I have when calling read().
As a bonus I can see the problem on the device itself:
The device is configured as you can see here on this screen [3].
It has two transmision LEDs: TX and RX. Blink duration is set for 100ms.
This is a recording before the bad commit when all is working fine: [4]
And this is with the bad commit: [5]
As you can see the TX led is blinking wrongly long (indicating transmission?)
and I have problems doing read() calls (EAGAIN).
Reported-by: Mariusz Bialonczyk <manio@skyboo.net>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Fixes: a81cf9799a ("cdc-acm: implement put_char() and flush_chars()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
wdm_in_callback() is a completion handler function for the USB driver.
So it should not sleep. But it calls service_outstanding_interrupt(),
which calls usb_submit_urb() with GFP_KERNEL.
To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC.
This bug is found by my static analysis tool DSAC.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
32 bit applications can only call ioctl functions on 64 bit systems
when the field .compat_ioctl is defined for file operations.
Tested-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
add USBTMC_IOCTL_CONFIG_TERMCHAR to control TermChar handling
for next read(). Controls field 'TermChar' and Bit 1 of field
'bmTransferAttributes' of REQUEST_DEV_DEP_MSG_IN BULK-OUT header.
Allows enabling/disabling of terminating a read on reception of
term_char individually for each read request.
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Tested-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
