From dce60e7efa97469498f835c931700922be5b763e Mon Sep 17 00:00:00 2001 From: Mathias Nyman Date: Mon, 10 Feb 2020 15:45:50 +0200 Subject: [PATCH] xhci: Force Maximum Packet size for Full-speed bulk devices to valid range. commit f148b9f402ef002b57bcff3964d45abc8ffb6c3f upstream. A Full-speed bulk USB audio device (DJ-Tech CTRL) with a invalid Maximum Packet Size of 4 causes a xHC "Parameter Error" at enumeration. This is because valid Maximum packet sizes for Full-speed bulk endpoints are 8, 16, 32 and 64 bytes. Hosts are not required to support other values than these. See usb 2 specs section 5.8.3 for details. The device starts working after forcing the maximum packet size to 8. This is most likely the case with other devices as well, so force the maximum packet size to a valid range. Cc: stable@vger.kernel.org Reported-by: Rene D Obermueller Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20200210134553.9144-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-mem.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 82ce6d8..1bbb652 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -1475,9 +1475,15 @@ int xhci_endpoint_init(struct xhci_hcd *xhci, /* Allow 3 retries for everything but isoc, set CErr = 3 */ if (!usb_endpoint_xfer_isoc(&ep->desc)) err_count = 3; - /* Some devices get this wrong */ - if (usb_endpoint_xfer_bulk(&ep->desc) && udev->speed == USB_SPEED_HIGH) - max_packet = 512; + /* HS bulk max packet should be 512, FS bulk supports 8, 16, 32 or 64 */ + if (usb_endpoint_xfer_bulk(&ep->desc)) { + if (udev->speed == USB_SPEED_HIGH) + max_packet = 512; + if (udev->speed == USB_SPEED_FULL) { + max_packet = rounddown_pow_of_two(max_packet); + max_packet = clamp_val(max_packet, 8, 64); + } + } /* xHCI 1.0 and 1.1 indicates that ctrl ep avg TRB Length should be 8 */ if (usb_endpoint_xfer_control(&ep->desc) && xhci->hci_version >= 0x100) avg_trb_len = 8; -- 2.7.4