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The old code in dwc2_process_periodic_channels() would only enable the "periodic empty" interrupt if we weren't using DMA. That wasn't right since we can still get into cases where we have small FIFOs even on systems that have DMA (the rk3288 is a prime example). Let's always enable/disable the "periodic empty" when appropriate. As part of this: * Always call dwc2_process_periodic_channels() even if there's nothing in periodic_sched_assigned (we move the queue empty check so we still avoid the extra work). That will make extra certain that we will properly disable the "periodic empty" interrupt even if there's nothing queued up. * Move the enable of "periodic empty" due to non-empty periodic_sched_assigned to be for slave mode (non-DMA mode) only. Presumably this was the original intention of the check for DMA since it seems to match the comments above where in slave mode we leave things on the assigned queue. Note that even before this change slave mode didn't work for me, so I can't say for sure that my understanding of slave mode is correct. However, this shouldn't change anything for slave mode so if slave mode worked for someone in the past it ought to still work. With this change, I no longer get constant misses reported by my other debugging code (and with future patches) when I've got: * Rockchip rk3288 Chromebook, using port ff540000 -> Pluggable 7-port Hub with Charging (powered) -> Microsoft Wireless Keyboard 2000 in port 1. -> Das Keyboard in port 2. -> Jabra Speaker in port 3 -> Logitech, Inc. Webcam C600 in port 4 -> Microsoft Sidewinder X6 Keyboard in port 5 ...and I'm playing music on the USB speaker and capturing video from the webcam. Acked-by: John Youn <johnyoun@synopsys.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Tested-by: Heiko Stuebner <heiko@sntech.de> Tested-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Felipe Balbi <balbi@kernel.org> |
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atm | ||
c67x00 | ||
chipidea | ||
class | ||
common | ||
core | ||
dwc2 | ||
dwc3 | ||
early | ||
gadget | ||
host | ||
image | ||
isp1760 | ||
misc | ||
mon | ||
musb | ||
phy | ||
renesas_usbhs | ||
serial | ||
storage | ||
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.