On Mon, 2 Jan 2012 12:05:02 +0200, Felipe Balbi <balbi@xxxxxx> wrote:
> According to USB 3.0 Specification Table 9-22, if
> bmAttributes [4:0] are set to zero, it means "no
> streams supported", but the way this helper was
> defined on Linux, we will *always* have one stream
> which might cause several problems.
>
> For example on DWC3, we would tell the controller
> endpoint has streams enable and yet start transfers
^^^ "enabled"?
> with Stream ID set to 0, which would goof up the host
> side.
>
> While doing that, convert the macro to an inline
> function due to the different checks we now need.
>
> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> ---
>
> this should be applied as far back as 2.6.35 (when the
> commit was first introduced), but of course the DWC3 part
> will only apply to 3.2-stable. You can safely ignore the
> DWC3 part for anything older than 3.2-stable and, hopefully,
> the patch should still apply.
>
> drivers/usb/dwc3/gadget.c | 3 +--
> drivers/usb/host/xhci.c | 3 +--
> include/linux/usb/ch9.h | 20 +++++++++++++++++++-
> 3 files changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 12975ac..76036d0 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -234,8 +234,7 @@ static int dwc3_gadget_set_ep_config(struct dwc3 *dwc, struct dwc3_ep *dep,
> params.param1 = DWC3_DEPCFG_XFER_COMPLETE_EN
> | DWC3_DEPCFG_XFER_NOT_READY_EN;
>
> - if (comp_desc && USB_SS_MAX_STREAMS(comp_desc->bmAttributes)
> - && usb_endpoint_xfer_bulk(desc)) {
> + if (usb_ss_max_streams(comp_desc) && usb_endpoint_xfer_bulk(desc)) {
> params.param1 |= DWC3_DEPCFG_STREAM_CAPABLE
> | DWC3_DEPCFG_STREAM_EVENT_EN;
> dep->stream_capable = true;
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index a1afb7c..b0d9ac6 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -2796,8 +2796,7 @@ static int xhci_calculate_streams_and_bitmask(struct xhci_hcd *xhci,
> if (ret < 0)
> return ret;
>
> - max_streams = USB_SS_MAX_STREAMS(
> - eps[i]->ss_ep_comp.bmAttributes);
> + max_streams = usb_ss_max_streams(&eps[i]->ss_ep_comp);
> if (max_streams < (*num_streams - 1)) {
> xhci_dbg(xhci, "Ep 0x%x only supports %u stream IDs.\n",
> eps[i]->desc.bEndpointAddress,
> diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
> index d5da6c6..61b2905 100644
> --- a/include/linux/usb/ch9.h
> +++ b/include/linux/usb/ch9.h
> @@ -605,8 +605,26 @@ struct usb_ss_ep_comp_descriptor {
> } __attribute__ ((packed));
>
> #define USB_DT_SS_EP_COMP_SIZE 6
> +
> /* Bits 4:0 of bmAttributes if this is a bulk endpoint */
> -#define USB_SS_MAX_STREAMS(p) (1 << ((p) & 0x1f))
> +static inline int
> +usb_ss_max_streams(const struct usb_ss_ep_comp_descriptor *comp)
> +{
> + int max_streams;
> +
> + if (!comp)
> + return 0;
> +
> + max_streams = comp->bmAttributes & 0x1f;
> +
> + if (!max_streams)
> + return 0;
> +
> + max_streams = 1 << max_streams;
> +
> + return max_streams;
> +}
> +
> /* Bits 1:0 of bmAttributes if this is an isoc endpoint */
> #define USB_SS_MULT(p) (1 + ((p) & 0x3))
>
> --
> 1.7.8.2
>
> --
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