linux_dsm_epyc7002

mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-12-02 15:36:42 +07:00

History

Alan Stern 004c196828 USB: EHCI: go back to using the system clock for QH unlinks This patch (as1477) fixes a problem affecting a few types of EHCI controller. Contrary to what one might expect, these controllers automatically stop their internal frame counter when no ports are enabled. Since ehci-hcd currently relies on the frame counter for determining when it should unlink QHs from the async schedule, those controllers run into trouble: The frame counter stops and the QHs never get unlinked. Some systems have also experienced other problems traced back to commit `b963801164` (USB: ehci-hcd unlink speedups), which made the original switch from using the system clock to using the frame counter. It never became clear what the reason was for these problems, but evidently it is related to use of the frame counter. To fix all these problems, this patch more or less reverts that commit and goes back to using the system clock. But this can't be done cleanly because other changes have since been made to the scan_async() subroutine. One of these changes involved the tricky logic that tries to avoid rescanning QHs that have already been seen when the scanning loop is restarted, which happens whenever an URB is given back. Switching back to clock-based unlinks would make this logic even more complicated. Therefore the new code doesn't rescan the entire async list whenever a giveback occurs. Instead it rescans only the current QH and continues on from there. This requires the use of a separate pointer to keep track of the next QH to scan, since the current QH may be unlinked while the scanning is in progress. That new pointer must be global, so that it can be adjusted forward whenever the _next_ QH gets unlinked. (uhci-hcd uses this same trick.) Simplification of the scanning loop removes a level of indentation, which accounts for the size of the patch. The amount of code changed is relatively small, and it isn't exactly a reversion of the `b963801164` commit. This fixes Bugzilla #32432. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@kernel.org> Tested-by: Matej Kenda <matejken@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>		2011-07-08 14:55:08 -07:00
..
atm	drivers: usb: atm: ueagle-atm: Add missing const qualifier	2011-07-08 14:51:30 -07:00
c67x00	Fix common misspellings	2011-03-31 11:26:23 -03:00
class	usb/class: use printk_ratelimited() instead of printk_ratelimit()	2011-07-01 14:43:24 -07:00
core	Merge 3.0-rc2 into usb-linus as it's needed by some USB patches	2011-06-14 06:51:23 -07:00
early	USB: EHCI: Support controllers with big endian capability regs	2011-05-03 11:43:21 -07:00
gadget	USB: s3c2410_udc: fix custom UDC command handling	2011-07-01 14:51:43 -07:00
host	USB: EHCI: go back to using the system clock for QH unlinks	2011-07-08 14:55:08 -07:00
image	Fix common misspellings	2011-03-31 11:26:23 -03:00
misc	Merge branch 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6	2011-05-23 12:33:02 -07:00
mon	USB: usbmon: fix-up docs and text API for sparse ISO	2011-02-04 11:46:57 -08:00
musb	usb: musb: no need to access platform_device	2011-07-01 14:31:15 -07:00
otg	USB: OTG: Use work_queue in set_vbus for TWL6030 transciever	2011-07-01 14:45:43 -07:00
renesas_usbhs	usb: renesas_usbhs: use dma handler	2011-07-01 14:43:27 -07:00
serial	USB: serial: add another 4N-GALAXY.DE PID to ftdi_sio driver	2011-06-08 13:48:30 -07:00
storage	Realtek cr: Add autosuspend function.	2011-07-01 14:53:42 -07:00
wusbcore	wusb: use printk_ratelimited() instead of printk_ratelimit()	2011-07-01 14:43:25 -07:00
Kconfig	usb: gadget: allow multiple gadgets to be built	2011-07-01 14:31:11 -07:00
Makefile	USB: fix build of FSL MPH DR OF platform driver	2011-05-02 16:59:37 -07:00
README
usb-skeleton.c	llseek: automatically add .llseek fop	2010-10-15 15:53:27 +02:00

README

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.