Re: [PATCH v2 2/2] usb: musb: Fix DMA desired mode for Mentor DMA engine

From: Sergei Shtylyov
Date: Tue Feb 09 2016 - 06:14:28 EST


Hello.

On 2/9/2016 1:15 AM, Joshua Henderson wrote:

From: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>

Commit 754fe4a92c07 ("usb: musb: Remove ifdefs for TX DMA for musb_host.c")
introduces a problem setting the desired channel mode for the Mentor DMA
engine.

There is a case where the pointer of the channel DMA mode is incorrectly
assigned to an address,

Pointer assigned to address? I don't see how that matches the code.

when it should be assigned the actual mode
value. This results in the value of channel->desired_mode not being
correct.

Signed-off-by: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>
Signed-off-by: Joshua Henderson <joshua.henderson@xxxxxxxxxxxxx>
---
Changes since v1:
- Fix commit comment citing the cause of the regression.
---
drivers/usb/musb/musb_host.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 6bef86f..b9e24862 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -662,7 +662,7 @@ static int musb_tx_dma_set_mode_mentor(struct dma_controller *dma,
csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
}
- channel->desired_mode = mode;
+ channel->desired_mode = *mode;
musb_writew(epio, MUSB_TXCSR, csr);

return 0;

MBR, Sergei