linux_dsm_epyc7002/drivers/usb
Douglas Anderson 0fe239bc19 usb: dwc2: Avoid double-reset at boot time
In (usb: dwc2: reset dwc2 core before dwc2_get_hwparams()) we added an
extra reset to the probe path for the dwc2 USB controllers.  This
allowed proper detection of parameters even if the firmware had already
used the USB part.

Unfortunately, this extra reset is quite slow and is affecting boot
speed.  We can avoid the double-reset by skipping the extra reset that
would happen just after the one we added.  Logic that explains why this
is safe:

* As of the CL mentioned above, we now always call dwc2_core_reset() in
  dwc2_driver_probe() before dwc2_hcd_init().

* The only caller of dwc2_hcd_init() is dwc2_driver_probe(), so we're
  guaranteed that dwc2_core_reset() was called before dwc2_hdc_init().

* dwc2_hdc_init() is the only caller that passes an irq other than -1 to
  dwc2_core_init().  Thus if dwc2_core_init() is called with an irq
  other than -1 we're guaranteed that dwc2_core_reset was called before
  dwc2_core_init().

...this allows us to remove the dwc2_core_reset() in dwc2_core_init() if
irq is not < 0.

Note that since "irq" wasn't used in the function dwc2_core_init()
anyway and since select_phy was always set at exactly the same times we
could avoid the reset, we remove "irq" and rename "select_phy" to
"initial_setup" and adjust the callers accordingly.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-12-22 11:52:08 -06:00
..
atm USB: atm: cxacru: fix blank line after declaration 2015-07-22 14:55:22 -07:00
c67x00 c67x00-hcd: use USB_DT_HUB 2015-04-03 19:03:16 +02:00
chipidea usb: chipidea: imx: fix a possible NULL dereference 2015-11-18 15:27:31 +08:00
class USB: cdc_acm: Ignore Infineon Flash Loader utility 2015-11-23 10:31:05 +01:00
common usb: of: add an api to get dr_mode by the phy node 2015-12-15 09:12:41 -06:00
core USB: add quirk for devices with broken LPM 2015-12-11 15:40:51 -08:00
dwc2 usb: dwc2: Avoid double-reset at boot time 2015-12-22 11:52:08 -06:00
dwc3 usb: dwc3: gadget: pass a condition to dev_WARN_ONCE() 2015-12-16 10:07:27 -06:00
early
gadget usb: gadget: Add the console support for usb-to-serial port 2015-12-22 11:49:39 -06:00
host xhci: fix usb2 resume timing and races. 2015-12-11 15:40:51 -08:00
image scsi: Do not set cmd_per_lun to 1 in the host template 2015-05-31 18:06:28 -07:00
isp1760 usb: isp1760: udc: add ep capabilities support 2015-08-04 12:26:55 -05:00
misc usb: misc: usbtest: Remove timeval usage 2015-12-15 09:12:41 -06:00
mon USB: mon_stat.c: move assignment out of if () block 2015-05-10 16:01:11 +02:00
musb usb: musb: Fix unbalanced pm_runtime_enable 2015-12-16 10:07:28 -06:00
phy usb: musb: core: Fix handling of the phy notifications 2015-12-16 10:07:28 -06:00
renesas_usbhs usb: renesas_usbhs: add fallback compatibility strings 2015-12-16 10:53:51 -06:00
serial USB: serial: Another Infineon flash loader USB ID 2015-11-23 10:32:59 +01:00
storage usb-storage: Fix scsi-sd failure "Invalid field in cdb" for USB adapter JMicron 2015-12-01 10:23:33 -08:00
usbip usbip: vhci_hcd: at unlink, return -EIDRM if vhci_rx took the urb 2015-10-04 10:59:03 +01:00
wusbcore wusbcore: rh: use USB_DT_HUB 2015-04-03 19:03:15 +02:00
Kconfig usb: isp1760: Move driver from drivers/usb/host/ to drivers/usb/isp1760/ 2015-01-27 09:39:38 -06:00
Makefile usb-host: Remove fusbh200 driver 2015-10-16 23:44:33 -07:00
README
usb-skeleton.c

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 ("hub_wq").

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.