Re: [PATCH] usb: dwc2: hcd: Fix host channel halt flow

From: Stefan Wahren
Date: Thu Dec 07 2017 - 12:15:03 EST


Hi Minas,

Am 07.12.2017 um 18:08 schrieb Stefan Wahren:
> According databook in Buffer and External DMA mode
> non-split periodic channels can't be halted.

do you know of any consequences not having this patch applied?

>
> Signed-off-by: Minas Harutyunyan <hminas@xxxxxxxxxxxx>

Please add a fixes tag.

Thanks
Stefan

> ---
> drivers/usb/dwc2/hcd.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
> index 614bb9603def..987122497408 100644
> --- a/drivers/usb/dwc2/hcd.c
> +++ b/drivers/usb/dwc2/hcd.c
> @@ -985,6 +985,25 @@ void dwc2_hc_halt(struct dwc2_hsotg *hsotg, struct dwc2_host_chan *chan,
>
> if (dbg_hc(chan))
> dev_vdbg(hsotg->dev, "%s()\n", __func__);
> +
> + /*
> + * In buffer DMA or external DMA mode channel can't be halted
> + * for non-split periodic channels. At the end of the next
> + * uframe/frame (in the worst case), the core generates a channel
> + * halted and disables the channel automatically.
> + */
> + if ((hsotg->core_params->dma_enable > 0 &&
> + hsotg->core_params->dma_desc_enable <= 0) ||
> + hsotg->hw_params.arch == GHWCFG2_EXT_DMA_ARCH) {
> + if (!chan->do_split &&
> + (chan->ep_type == USB_ENDPOINT_XFER_ISOC ||
> + chan->ep_type == USB_ENDPOINT_XFER_INT)) {
> + dev_err(hsotg->dev, "%s() Channel can't be halted\n",
> + __func__);
> + return;
> + }
> + }
> +
> if (halt_status == DWC2_HC_XFER_NO_HALT_STATUS)
> dev_err(hsotg->dev, "!!! halt_status = %d !!!\n", halt_status);
>