linux_dsm_epyc7002/drivers/usb
Stefan Becker de85422b94 USB: fix interrupt disabling for HCDs with shared interrupt handlers
USB: fix interrupt disabling for HCDs with shared interrupt handlers

As has been discussed several times on LKML, IRQF_SHARED | IRQF_DISABLED
doesn't work reliably, i.e. a shared interrupt handler CAN'T be certain to
be called with interrupts disabled. Most USB HCD handlers use IRQF_DISABLED
and therefore havoc can break out if they share their interrupt with a
handler that doesn't use it.

On my test machine the yenta_socket interrupt handler (no IRQF_DISABLED)
was registered before ehci_hcd and one uhci_hcd instance. Therefore all
usb_hcd_irq() invocations for ehci_hcd and for one uhci_hcd instance
happened with interrupts enabled. That led to random lockups as USB core
HCD functions that acquire the same spinlock could be called twice
from interrupt handlers.

This patch updates usb_hcd_irq() to always disable/restore interrupts.
usb_add_hcd() will silently remove any IRQF_DISABLED requested from HCD code.

Signed-off-by: Stefan Becker <stefan.becker@nokia.com>
Cc: stable <stable@kernel.org>
Acked-by: David Brownell <david-b@pacbell.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-03 18:20:37 -07:00
..
atm USB: Remove redundant dependencies on USB_ATM. 2008-05-02 10:25:57 -07:00
c67x00 usb/c67x00 endianness annotations 2008-06-04 08:06:01 -07:00
class USB: fix cdc-acm resume() 2008-07-03 18:20:36 -07:00
core USB: fix interrupt disabling for HCDs with shared interrupt handlers 2008-07-03 18:20:37 -07:00
gadget USB: fsl_usb2_udc: fix recursive lock 2008-05-29 13:59:06 -07:00
host USB: ohci - record data toggle after unlink 2008-07-03 18:20:36 -07:00
image usb: replace remaining __PRETTY_FUNCTION__ occurrences 2008-04-24 21:16:48 -07:00
misc sisusbvga: Fix oops on disconnect. 2008-07-03 18:20:37 -07:00
mon usbmon: restore mmap 2008-04-24 21:16:43 -07:00
serial USB: New device ID for ftdi_sio driver 2008-07-03 18:20:37 -07:00
storage USB: mass storage: new id for US_SC_CYP_ATACB 2008-07-03 18:20:36 -07:00
Kconfig USB: add support for SuperH OHCI 2008-02-01 14:35:03 -08:00
Makefile USB: add Cypress c67x00 OTG controller HCD driver 2008-05-02 10:25:57 -07:00
README USB: fix directory references in usb/README 2007-11-28 13:58:34 -08:00
usb-skeleton.c USB: remove unnecessary type casting of urb->context 2008-04-24 21:16:55 -07:00

To understand all the Linux-USB framework, you'll use these resources:

    * This source code.  This is necessarily an evolving work, and
      includes kerneldoc that should help you get a current overview.
      ("make pdfdocs", and then look at "usb.pdf" for host side and
      "gadget.pdf" for peripheral side.)  Also, Documentation/usb has
      more information.

    * The USB 2.0 specification (from www.usb.org), with supplements
      such as those for USB OTG and the various device classes.
      The USB specification has a good overview chapter, and USB
      peripherals conform to the widely known "Chapter 9".

    * Chip specifications for USB controllers.  Examples include
      host controllers (on PCs, servers, and more); peripheral
      controllers (in devices with Linux firmware, like printers or
      cell phones); and hard-wired peripherals like Ethernet adapters.

    * Specifications for other protocols implemented by USB peripheral
      functions.  Some are vendor-specific; others are vendor-neutral
      but just standardized outside of the www.usb.org team.

Here is a list of what each subdirectory here is, and what is contained in
them.

core/		- This is for the core USB host code, including the
		  usbfs files and the hub class driver ("khubd").

host/		- This is for USB host controller drivers.  This
		  includes UHCI, OHCI, EHCI, and others that might
		  be used with more specialized "embedded" systems.

gadget/		- This is for USB peripheral controller drivers and
		  the various gadget drivers which talk to them.


Individual USB driver directories.  A new driver should be added to the
first subdirectory in the list below that it fits into.

image/		- This is for still image drivers, like scanners or
		  digital cameras.
../input/	- This is for any driver that uses the input subsystem,
		  like keyboard, mice, touchscreens, tablets, etc.
../media/	- This is for multimedia drivers, like video cameras,
		  radios, and any other drivers that talk to the v4l
		  subsystem.
../net/		- This is for network drivers.
serial/		- This is for USB to serial drivers.
storage/	- This is for USB mass-storage drivers.
class/		- This is for all USB device drivers that do not fit
		  into any of the above categories, and work for a range
		  of USB Class specified devices. 
misc/		- This is for all USB device drivers that do not fit
		  into any of the above categories.