Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1329641 > unrolled thread

[PATCH v2 1/2] usb: musb: Fix DMA for host mode

Started byJoshua Henderson <joshua.henderson@microchip.com>
First post2016-02-08 23:20 +0100
Last post2016-02-09 12:10 +0100
Articles 2 — 2 participants

Back to article view | Back to linux.kernel


Contents

  [PATCH v2 1/2] usb: musb: Fix DMA for host mode Joshua Henderson <joshua.henderson@microchip.com> - 2016-02-08 23:20 +0100
    Re: [PATCH v2 1/2] usb: musb: Fix DMA for host mode Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-02-09 12:10 +0100

#1329641 — [PATCH v2 1/2] usb: musb: Fix DMA for host mode

FromJoshua Henderson <joshua.henderson@microchip.com>
Date2016-02-08 23:20 +0100
Subject[PATCH v2 1/2] usb: musb: Fix DMA for host mode
Message-ID<r02k2-2Zq-7@gated-at.bofh.it>
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;
-			else
+			} else
 				dev_err(musb->controller, "error: rx_dma failed\n");
 		}
 
-- 
1.7.9.5

[toc] | [next] | [standalone]


#1330091

FromSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Date2016-02-09 12:10 +0100
Message-ID<r0elc-3c6-3@gated-at.bofh.it>
In reply to#1329641
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

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web