Hi Felipe,
Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> writes:
< snip >
> thinking about this a little more. This extra list_empty() check is
> not wrong at all :-) I've amended this series with the 3 patches
> below. I'll resend the series once I've given more time for people to
> test. Patches have been updated to the branch on kernel.org as well,
> btw.
< snip >
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 9d4dc8bed644..9cf89f3cf203 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -1233,6 +1233,8 @@ static int __dwc3_gadget_get_frame(struct dwc3 *dwc)
> return DWC3_DSTS_SOFFN(reg);
> }
>
> +#define DWC3_ALIGN_FRAME(d) (((d)->frame_number + (d)->interval) & ~((d)->interval - 1))
> +
> static void __dwc3_gadget_start_isoc(struct dwc3_ep *dep)
> {
> if (list_empty(&dep->pending_list)) {
> @@ -1242,11 +1244,7 @@ static void __dwc3_gadget_start_isoc(struct dwc3_ep *dep)
> return;
> }
>
> - /*
> - * Schedule the first trb for one interval in the future or at
> - * least 4 microframes.
> - */
> - dep->frame_number += max_t(u32, 4, dep->interval);
> + dep->frame_number = DWC3_ALIGN_FRAME(dep);
> __dwc3_gadget_kick_transfer(dep);
> }
Pretty sure this could cause problems. Instead of starting at least 4 uframes
in the future, this will now try to start at the next aligned uframe. If
dep->interval is very small (say 1) and we are almost at the end of the
current uframe, there might not be enough time?
--
Paul
--
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
