lkml.org 
[lkml]   [2016]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2 1/2] usb: musb: Fix DMA for host mode
From
Date
On 2/9/2016 1:15 AM, Joshua Henderson wrote:

> From: Cristian Birsan <cristian.birsan@microchip.com>
>
> Commit ac33cdb16681 ("usb: musb: Remove ifdefs for musb_host_rx in
> musb_host.c part5") introduces a problem setting DMA host mode.
>
> This commit fixes the done condition that advances the musb schedule.
> Without this patch the the msub_advance_schedule() is called immediately
> after receiving an endpoint rx interrupt without waiting for the dma
> transfer to complete. As a consequence when the dma complete interrupt
> arrives the in_qh member of hw_ep is already null an the musb_host_rx()
> exits on !urb error case.
>
> Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
> Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
> ---
> Changes since v1:
> - Don't add unecessary new variable. Just correct done.
> ---
> drivers/usb/musb/musb_host.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> index 795a45b..6bef86f 100644
> --- a/drivers/usb/musb/musb_host.c
> +++ b/drivers/usb/musb/musb_host.c
> @@ -2006,9 +2006,15 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> done = musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh,
> urb, xfer_len,
> iso_err);
> - if (done)
> + if (done) {
> + /* Don't call msub_advance_schedule()
> + * immediately after receiving an endpoint RX
> + * interrupt without waiting for the DMA
> + * transfer to complete.
> + */
> + done = false;
> goto finish;

By not needing the 'ret' variable I meant that you should just call
musb_rx_dma_in_inventra_cppi41() directly from *if*.

> - else
> + } else
> dev_err(musb->controller, "error: rx_dma failed\n");

Need to enclose all branches in {} if at least one is enclosed.

MBR, Sergei

\
 
 \ /
  Last update: 2016-02-09 12:21    [W:0.040 / U:17.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site