On 10.07.2017 18:52, Marc Zyngier wrote:
The Renesas uPD72020x XHCI controller seems to suffer from a really annoying bug, where it may retain some of its DMA programming across a XHCI reset, and despite the driver correctly programming new DMA addresses. This is visible if the device has been using 64bit DMA addresses, and is then switched to using 32bit DMA addresses. The top 32bits of the address (now zero) are ignored are replaced by the 32bit from the *previous* programming. Sticking with 64bit DMA always works, but doesn't seem very appropriate. A PCI reset of the device restores the normal functionnality, which is done at probe time. Unfortunately, this has to be done before any quirk has been discovered, hence the intrusive nature of the fix. Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> --- drivers/usb/host/pci-quirks.c | 20 ++++++++++++++++++++ drivers/usb/host/pci-quirks.h | 1 + drivers/usb/host/xhci-pci.c | 7 +++++++ 3 files changed, 28 insertions(+)
Acked-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
