mirror of
https://github.com/hardkernel/linux.git
synced 2026-05-30 07:46:36 +09:00
2761a63945
'ARM: OMAP3: USB: Fix the EHCI ULPI PHY reset issue' (1fcb57d0) fixes an issue where the ULPI PHYs were not held in reset while initializing the EHCI controller. However, it also changes behavior in omap-usb-host.c omap_usbhs_init by releasing reset while the configuration in that function was done. This change caused a regression on BB-xM where USB would not function if 'usb start' had been run from u-boot before booting. A change was made to release reset a little bit earlier which fixed the issue on BB-xM and did not cause any regressions on 3430 sdp, the board for which the fix was originally made. This new fix, 'USB: EHCI: OMAP: Finish ehci omap phy reset cycle before adding hcd.', (3aa2ae74) caused a regression on OMAP5. The original fix to hold the EHCI controller in reset during initialization was correct, however it appears that changing omap_usbhs_init to not hold the PHYs in reset during it's configuration was incorrect. This patch first reverts both fixes, and then changes ehci_hcd_omap_probe in ehci-omap.c to hold the PHYs in reset as the original patch had done. It also is sure to incorporate the _cansleep change that has been made in the meantime. I've tested this on Beagleboard xM, I'd really like to get an ack from the 3430 sdp and OMAP5 guys before getting this merged. v3 - Brown paper bag its too early in the morning actually run git commit amend fix v2 - Put cansleep gpiolib call outside of spinlock Acked-by: Mantesh Sarashetti <mantesh@ti.com> Tested-by: Mantesh Sarashetti <mantesh@ti.com> Acked-by: Keshava Munegowda <keshava_mgowda@ti.com> Tested-by: Keshava Munegowda <keshava_mgowda@ti.com> Signed-off-by: Russ Dill <Russ.Dill@gmail.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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.