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The dwc3 driver can overwite its previous events if its top-half IRQ handler (TH) gets invoked again before processing the events in the cache. We see this as a hang in the file transfer and the host will attempt to reset the device. TH gets the event count and deasserts the interrupt line by writing DWC3_GEVNTSIZ_INTMASK to DWC3_GEVNTSIZ. If there's a new event coming between reading the event count and interrupt deassertion, dwc3 will lose previous pending events. More generally, we will see 0 event count, which should not affect anything. This shouldn't be possible in the current dwc3 implementation. However, through testing and reading the PCIe trace, the TH occasionally still gets invoked one more time after HW interrupt deassertion. (With PCIe legacy interrupts, TH is called repeatedly as long as the interrupt line is asserted). We suspect that there is a small detection delay in the SW. To avoid this issue, Check DWC3_EVENT_PENDING flag to determine if the events are processed in the bottom-half IRQ handler. If not, return IRQ_HANDLED and don't process new event. Cc: stable@vger.kernel.org Signed-off-by: Thinh Nguyen <thinhn@synopsys.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> |
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| atm | ||
| c67x00 | ||
| chipidea | ||
| class | ||
| common | ||
| core | ||
| dwc2 | ||
| dwc3 | ||
| early | ||
| gadget | ||
| host | ||
| image | ||
| isp1760 | ||
| misc | ||
| mon | ||
| mtu3 | ||
| musb | ||
| phy | ||
| renesas_usbhs | ||
| serial | ||
| storage | ||
| typec | ||
| usbip | ||
| wusbcore | ||
| Kconfig | ||
| Makefile | ||
| 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.