dma: imx-sdma: Fix the event id check to include RX event for UART6

Commit Message

Frieder Schrempf Feb. 24, 2020, 5:22 p.m. UTC

From: Frieder Schrempf <[e-mail]>

On i.MX6 the DMA event for the RX channel of UART6 is '0'. To fix
the broken DMA support for UART6, we change the check for event_id0
to include '0' as a valid id.

Fixes: 1ec1e82f2510 ("dmaengine: Add Freescale i.MX SDMA support")
Cc: [e-mail]
Signed-off-by: Frieder Schrempf <[e-mail]>
---
 drivers/dma/imx-sdma.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Fabio Estevam Feb. 24, 2020, 6:43 p.m. UTC | #1

Hi Frieder,

On Mon, Feb 24, 2020 at 2:22 PM Schrempf Frieder
<[e-mail]> wrote:
>
> From: Frieder Schrempf <[e-mail]>
>
> On i.MX6 the DMA event for the RX channel of UART6 is '0'. To fix

I would suggest being a bit more specific than saying i.MX6.

I see UART6 is present on i.MX6UL/i.MX6SX, but not on i.MX6Q/i.MX6DL,
so it would be better to specify it in the commit log.

imx6ul.dtsi does not have dma nodes under uart6, so I guess you fixed
it for imx6sx.

> the broken DMA support for UART6, we change the check for event_id0
> to include '0' as a valid id.
>
> Fixes: 1ec1e82f2510 ("dmaengine: Add Freescale i.MX SDMA support")
> Cc: [e-mail]
> Signed-off-by: Frieder Schrempf <[e-mail]>

Reviewed-by: Fabio Estevam <[e-mail]>

Vinod Koul Feb. 25, 2020, 6:12 a.m. UTC | #2

On 24-02-20, 15:43, Fabio Estevam wrote:
> Hi Frieder,
> 
> On Mon, Feb 24, 2020 at 2:22 PM Schrempf Frieder
> <[e-mail]> wrote:
> >
> > From: Frieder Schrempf <[e-mail]>
> >
> > On i.MX6 the DMA event for the RX channel of UART6 is '0'. To fix
> 
> I would suggest being a bit more specific than saying i.MX6.
> 
> I see UART6 is present on i.MX6UL/i.MX6SX, but not on i.MX6Q/i.MX6DL,
> so it would be better to specify it in the commit log.
> 
> imx6ul.dtsi does not have dma nodes under uart6, so I guess you fixed
> it for imx6sx.

and use right subsystem tag dmaengine. Git log of the file should tell
you the right one to use :)

> 
> > the broken DMA support for UART6, we change the check for event_id0
> > to include '0' as a valid id.
> >
> > Fixes: 1ec1e82f2510 ("dmaengine: Add Freescale i.MX SDMA support")
> > Cc: [e-mail]
> > Signed-off-by: Frieder Schrempf <[e-mail]>
> 
> Reviewed-by: Fabio Estevam <[e-mail]>

Frieder Schrempf Feb. 25, 2020, 8:01 a.m. UTC | #3

Hi Fabio,

On 24.02.20 19:43, Fabio Estevam wrote:
> Hi Frieder,
> 
> On Mon, Feb 24, 2020 at 2:22 PM Schrempf Frieder
> <[e-mail]> wrote:
>>
>> From: Frieder Schrempf <[e-mail]>
>>
>> On i.MX6 the DMA event for the RX channel of UART6 is '0'. To fix
> 
> I would suggest being a bit more specific than saying i.MX6.
> 
> I see UART6 is present on i.MX6UL/i.MX6SX, but not on i.MX6Q/i.MX6DL,
> so it would be better to specify it in the commit log.
> 
> imx6ul.dtsi does not have dma nodes under uart6, so I guess you fixed
> it for imx6sx.

Sounds reasonable. I will change the commit message to refer to 
i.MX6UL/ULL/SX.

Actually one of our customers has a dts for i.MX6UL, that enables the 
DMA for UART6. The DMA not being enabled in imx6ul.dtsi doesn't mean no 
one is using it. Actually I have no idea why it's enabled by default for 
i.MX6SX and disabled by default for i.MX6UL.

Thanks,
Frieder

> 
>> the broken DMA support for UART6, we change the check for event_id0
>> to include '0' as a valid id.
>>
>> Fixes: 1ec1e82f2510 ("dmaengine: Add Freescale i.MX SDMA support")
>> Cc: [e-mail]
>> Signed-off-by: Frieder Schrempf <[e-mail]>
> 
> Reviewed-by: Fabio Estevam <[e-mail]>
>

Frieder Schrempf Feb. 25, 2020, 8:03 a.m. UTC | #4

On 25.02.20 07:12, Vinod Koul wrote:
> On 24-02-20, 15:43, Fabio Estevam wrote:
>> Hi Frieder,
>>
>> On Mon, Feb 24, 2020 at 2:22 PM Schrempf Frieder
>> <[e-mail]> wrote:
>>>
>>> From: Frieder Schrempf <[e-mail]>
>>>
>>> On i.MX6 the DMA event for the RX channel of UART6 is '0'. To fix
>>
>> I would suggest being a bit more specific than saying i.MX6.
>>
>> I see UART6 is present on i.MX6UL/i.MX6SX, but not on i.MX6Q/i.MX6DL,
>> so it would be better to specify it in the commit log.
>>
>> imx6ul.dtsi does not have dma nodes under uart6, so I guess you fixed
>> it for imx6sx.
> 
> and use right subsystem tag dmaengine. Git log of the file should tell
> you the right one to use :)

Sorry, my bad. I will fix it.

> 
>>
>>> the broken DMA support for UART6, we change the check for event_id0
>>> to include '0' as a valid id.
>>>
>>> Fixes: 1ec1e82f2510 ("dmaengine: Add Freescale i.MX SDMA support")
>>> Cc: [e-mail]
>>> Signed-off-by: Frieder Schrempf <[e-mail]>
>>
>> Reviewed-by: Fabio Estevam <[e-mail]>
>

Patch

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 066b21a32232..3d4aac97b1fc 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -1331,7 +1331,7 @@  static void sdma_free_chan_resources(struct dma_chan *chan)
 
 	sdma_channel_synchronize(chan);
 
-	if (sdmac->event_id0)
+	if (sdmac->event_id0 >= 0)
 		sdma_event_disable(sdmac, sdmac->event_id0);
 	if (sdmac->event_id1)
 		sdma_event_disable(sdmac, sdmac->event_id1);
@@ -1631,7 +1631,7 @@  static int sdma_config(struct dma_chan *chan,
 	memcpy(&sdmac->slave_config, dmaengine_cfg, sizeof(*dmaengine_cfg));
 
 	/* Set ENBLn earlier to make sure dma request triggered after that */
-	if (sdmac->event_id0) {
+	if (sdmac->event_id0 >= 0) {
 		if (sdmac->event_id0 >= sdmac->sdma->drvdata->num_events)
 			return -EINVAL;
 		sdma_event_enable(sdmac, sdmac->event_id0);