[RFC] [PATCH] usb: gadget: fix dtd dma confusion

[Christoph Fritz]

On Wed, May 09, 2012 at 02:02:22AM +0200, Christoph Fritz wrote:
> 
> Hi to All,
> 
> after a while of testing and searching I can come up with a patch
> that fixes g_ether <-> iperf for fsl_udc on ARM i.MX35.
> 
> The sad part is that this kind of fix is already implemented for
> marvell mv_udc driver since last year but still _not_ in the ~15
> other *udc.c drivers.
> 
> See here:
> daec765da767e4a6a30e1298862b28f2cae9a73f
> usb: gadget: mv_udc: fix dtd dma confusion
> 
> So hereby I'm CC-ing all *udc.c maintainers to point out that this
> issue maybe affects you too.
> 
> 
> ---
> Subject: [PATCH] usb: gadget: fsl_udc: fix dtd dma confusion
> 
> The controller will hang when doing testings with g_ether and iperf
> (tool for measuring maximum TCP and UDP bandwidth).  This patch adds a
> delay to wait for controller to release dtd dma before freeing it.
> 
> Signed-off-by: Christoph Fritz <chf.fritz at googlemail.com>
> ---
>  drivers/usb/gadget/fsl_udc_core.c |    9 +++++++++
>  1 files changed, 9 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/usb/gadget/fsl_udc_core.c b/drivers/usb/gadget/fsl_udc_core.c
> index 55abfb6..fc86108 100644
> --- a/drivers/usb/gadget/fsl_udc_core.c
> +++ b/drivers/usb/gadget/fsl_udc_core.c
> @@ -1638,6 +1638,15 @@ static int process_ep_req(struct fsl_udc *udc, int pipe,
>  			status = REQ_UNCOMPLETE;
>  			return status;
>  		} else if (remaining_length) {
> +			/* wait controller release dtd dma */
> +			while ((curr_qh->curr_dtd_ptr == curr_td->td_dma)) {
> +				if (curr_td->next_td_ptr ==
> +						EP_QUEUE_HEAD_NEXT_TERMINATE) {
> +					udelay(100);
> +					break;
> +				}
> +				udelay(1);
> +			}
>  			if (direction) {
>  				VDBG("Transmit dTD remaining length not zero");
>  				status = -EPROTO;
> -- 
> 1.7.2.5

 ping  -  what about this patch? Will it be applied?

Thanks,
 -- Christoph