Re: [PATCH] usb: dwc2: host: fix the data toggle error in full speed descriptor dma

[John Youn]

On 1/25/2016 10:20 PM, Jianqiang Tang wrote:
> From: "Tang, Jianqiang" <jianqiang.tang@xxxxxxxxx>
> 
> There will be data toggle error happen for full speed buld-out transfer.
> The data toggle bit is saved in qh for non-control transfers, it is wrong
> to  check the qtd for that case.
> 
> Also fix one static analysis tool issue after fix the data toggle error.
> 
> Signed-off-by: Dyson Lee <dyson.lee@xxxxxxxxx>
> Signed-off-by: Tang, Jianqiang <jianqiang.tang@xxxxxxxxx>
> ---
>  drivers/usb/dwc2/hcd_ddma.c | 2 +-
>  drivers/usb/dwc2/hcd_intr.c | 4 ++++
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc2/hcd_ddma.c b/drivers/usb/dwc2/hcd_ddma.c
> index 36606fc..6b18956 100644
> --- a/drivers/usb/dwc2/hcd_ddma.c
> +++ b/drivers/usb/dwc2/hcd_ddma.c
> @@ -1258,7 +1258,7 @@ static void dwc2_complete_non_isoc_xfer_ddma(struct dwc2_hsotg *hsotg,
>  		 */
>  		if (halt_status == DWC2_HC_XFER_STALL)
>  			qh->data_toggle = DWC2_HC_PID_DATA0;
> -		else if (qtd)
> +		else
>  			dwc2_hcd_save_data_toggle(hsotg, chan, chnum, qtd);
>  	}
>  
> diff --git a/drivers/usb/dwc2/hcd_intr.c b/drivers/usb/dwc2/hcd_intr.c
> index f825380..918773f 100644
> --- a/drivers/usb/dwc2/hcd_intr.c
> +++ b/drivers/usb/dwc2/hcd_intr.c
> @@ -530,6 +530,10 @@ void dwc2_hcd_save_data_toggle(struct dwc2_hsotg *hsotg,
>  		else
>  			chan->qh->data_toggle = DWC2_HC_PID_DATA1;
>  	} else {
> +		if (!qtd) {
> +			dev_err(hsotg->dev, "qtd is null, return\n");
> +			return;
> +		}
>  		if (pid == TSIZ_SC_MC_PID_DATA0)
>  			qtd->data_toggle = DWC2_HC_PID_DATA0;
>  		else
> 

Thanks for this. I've applied this internally for testing and added
WARNs in the dwc2_hcd_save_data_toggle function(). I will resend for
review along with another fix that we have for DDMA in that same area.

Regards,
John