Atmel UART with dma enabled does not work on branch 5.4.Y from version 5.4.174.

Atmel UART with dma enabled does not work on branch 5.4.Y from version 5.4.174.

[Mickael GARDET]

Hi,

we observed a regression on our atmel platforms on branch 5.4.Y from 
version 5.4.174.
uarts are no longer functional if DMA is enabled.

the following patch
Commit e6af9b05bec63cd4d1de2a33968cd0be2a91282a dmaengine: at_xdmac: 
Start transfer for cyclic channels in issue_pending
Link:
https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.com
has not been backported but is needed if the patch
Commit 4f4b9b5895614eb2e2b5f4cab7858f44bd113e1b tty: serial: atmel: Call 
dma_async_issue_pending()
Link: 
https://lore.kernel.org/r/20211125090028.786832-4-tudor.ambarus@microchip.com
is applied.

enclosed commit fix this issue and work for me.

Best regards,
Mickael GARDET

 From 9877f93c066be8c2f4e33a6edd4dfa3d6d6974d9 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus@microchip.com>
Date: Wed, 15 Dec 2021 13:01:05 +0200
Subject: [PATCH] dmaengine: at_xdmac: Start transfer for cyclic channels 
in issue_pending

commit e6af9b05bec63cd4d1de2a33968cd0be2a91282a upstream.

Cyclic channels must too call issue_pending in order to start a transfer.
Start the transfer in issue_pending regardless of the type of channel.
This wrongly worked before, because in the past the transfer was started
at tx_submit level when only a desc in the transfer list.

Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel 
eXtended DMA Controller driver")
Change-Id: If1bf3e13329cebb9904ae40620f6cf2b7f06fe9f
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: 
https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
drivers/dma/at_xdmac.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index f63d141481a3..9aae6b3da356 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1726,11 +1726,13 @@ static irqreturn_t at_xdmac_interrupt(int irq,
void *dev_id)
static void at_xdmac_issue_pending(struct dma_chan *chan)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
+    unsigned long flags;

dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);

-    if (!at_xdmac_chan_is_cyclic(atchan))
-        at_xdmac_advance_work(atchan);
+    spin_lock_irqsave(&atchan->lock, flags);
+    at_xdmac_advance_work(atchan);
+    spin_unlock_irqrestore(&atchan->lock, flags);

return;
}

base-commit: 7b3eb66d0daf61e91cccdb2fe5d271ae5adc5a76

-- 
2.35.1

Re: Atmel UART with dma enabled does not work on branch 5.4.Y from version 5.4.174.

[Greg KH]

On Fri, Feb 18, 2022 at 09:40:55AM +0100, Mickael GARDET wrote:
> Hi,
> 
> we observed a regression on our atmel platforms on branch 5.4.Y from version
> 5.4.174.
> uarts are no longer functional if DMA is enabled.
> 
> the following patch
> Commit e6af9b05bec63cd4d1de2a33968cd0be2a91282a dmaengine: at_xdmac: Start
> transfer for cyclic channels in issue_pending
> Link:
> https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.com
> has not been backported but is needed if the patch
> Commit 4f4b9b5895614eb2e2b5f4cab7858f44bd113e1b tty: serial: atmel: Call
> dma_async_issue_pending()
> Link:
> https://lore.kernel.org/r/20211125090028.786832-4-tudor.ambarus@microchip.com
> is applied.
> 
> enclosed commit fix this issue and work for me.
> 
> Best regards,
> Mickael GARDET
> 
> From 9877f93c066be8c2f4e33a6edd4dfa3d6d6974d9 Mon Sep 17 00:00:00 2001
> From: Tudor Ambarus <tudor.ambarus@microchip.com>
> Date: Wed, 15 Dec 2021 13:01:05 +0200
> Subject: [PATCH] dmaengine: at_xdmac: Start transfer for cyclic channels in
> issue_pending
> 
> commit e6af9b05bec63cd4d1de2a33968cd0be2a91282a upstream.
> 
> Cyclic channels must too call issue_pending in order to start a transfer.
> Start the transfer in issue_pending regardless of the type of channel.
> This wrongly worked before, because in the past the transfer was started
> at tx_submit level when only a desc in the transfer list.
> 
> Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended
> DMA Controller driver")
> Change-Id: If1bf3e13329cebb9904ae40620f6cf2b7f06fe9f
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> Link:
> https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.com
> Signed-off-by: Vinod Koul <vkoul@kernel.org>
> ---
> drivers/dma/at_xdmac.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
> index f63d141481a3..9aae6b3da356 100644
> --- a/drivers/dma/at_xdmac.c
> +++ b/drivers/dma/at_xdmac.c
> @@ -1726,11 +1726,13 @@ static irqreturn_t at_xdmac_interrupt(int irq,
> void *dev_id)
> static void at_xdmac_issue_pending(struct dma_chan *chan)
> {
> struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> +    unsigned long flags;
> 
> dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
> 
> -    if (!at_xdmac_chan_is_cyclic(atchan))
> -        at_xdmac_advance_work(atchan);
> +    spin_lock_irqsave(&atchan->lock, flags);
> +    at_xdmac_advance_work(atchan);
> +    spin_unlock_irqrestore(&atchan->lock, flags);
> 
> return;
> }
> 
> base-commit: 7b3eb66d0daf61e91cccdb2fe5d271ae5adc5a76
> 
> -- 
> 2.35.1
> 

The patch is whitespace damaged and can not be applied at all :(

Can you try fixing your email client up, or worst case, attach the
patch, and we can take it from there?

Also be sure to sign-off on the patch, as you have modified it to work
properly on this branch.

thanks,

greg k-h

Re: Atmel UART with dma enabled does not work on branch 5.4.Y from version 5.4.174.

[Mickael GARDET]

[-- Attachment #1: Type: text/plain, Size: 3105 bytes --]

Yes sorry,

enclosed signed patch.


Le 18/02/2022 à 09:46, Greg KH a écrit :
> On Fri, Feb 18, 2022 at 09:40:55AM +0100, Mickael GARDET wrote:
>> Hi,
>>
>> we observed a regression on our atmel platforms on branch 5.4.Y from version
>> 5.4.174.
>> uarts are no longer functional if DMA is enabled.
>>
>> the following patch
>> Commit e6af9b05bec63cd4d1de2a33968cd0be2a91282a dmaengine: at_xdmac: Start
>> transfer for cyclic channels in issue_pending
>> Link:
>> https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.com
>> has not been backported but is needed if the patch
>> Commit 4f4b9b5895614eb2e2b5f4cab7858f44bd113e1b tty: serial: atmel: Call
>> dma_async_issue_pending()
>> Link:
>> https://lore.kernel.org/r/20211125090028.786832-4-tudor.ambarus@microchip.com
>> is applied.
>>
>> enclosed commit fix this issue and work for me.
>>
>> Best regards,
>> Mickael GARDET
>>
>>  From 9877f93c066be8c2f4e33a6edd4dfa3d6d6974d9 Mon Sep 17 00:00:00 2001
>> From: Tudor Ambarus <tudor.ambarus@microchip.com>
>> Date: Wed, 15 Dec 2021 13:01:05 +0200
>> Subject: [PATCH] dmaengine: at_xdmac: Start transfer for cyclic channels in
>> issue_pending
>>
>> commit e6af9b05bec63cd4d1de2a33968cd0be2a91282a upstream.
>>
>> Cyclic channels must too call issue_pending in order to start a transfer.
>> Start the transfer in issue_pending regardless of the type of channel.
>> This wrongly worked before, because in the past the transfer was started
>> at tx_submit level when only a desc in the transfer list.
>>
>> Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended
>> DMA Controller driver")
>> Change-Id: If1bf3e13329cebb9904ae40620f6cf2b7f06fe9f
>> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
>> Link:
>> https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.com
>> Signed-off-by: Vinod Koul <vkoul@kernel.org>
>> ---
>> drivers/dma/at_xdmac.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
>> index f63d141481a3..9aae6b3da356 100644
>> --- a/drivers/dma/at_xdmac.c
>> +++ b/drivers/dma/at_xdmac.c
>> @@ -1726,11 +1726,13 @@ static irqreturn_t at_xdmac_interrupt(int irq,
>> void *dev_id)
>> static void at_xdmac_issue_pending(struct dma_chan *chan)
>> {
>> struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
>> +    unsigned long flags;
>>
>> dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
>>
>> -    if (!at_xdmac_chan_is_cyclic(atchan))
>> -        at_xdmac_advance_work(atchan);
>> +    spin_lock_irqsave(&atchan->lock, flags);
>> +    at_xdmac_advance_work(atchan);
>> +    spin_unlock_irqrestore(&atchan->lock, flags);
>>
>> return;
>> }
>>
>> base-commit: 7b3eb66d0daf61e91cccdb2fe5d271ae5adc5a76
>>
>> -- 
>> 2.35.1
>>
> 
> The patch is whitespace damaged and can not be applied at all :(
> 
> Can you try fixing your email client up, or worst case, attach the
> patch, and we can take it from there?
> 
> Also be sure to sign-off on the patch, as you have modified it to work
> properly on this branch.
> 
> thanks,
> 
> greg k-h

[-- Attachment #2: 0001-dmaengine-at_xdmac-Start-transfer-for-cyclic-channel.patch --]
[-- Type: text/x-patch, Size: 1737 bytes --]

From 1310f5ba2f2d199e6527d2a289192ff99d8c6c83 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus@microchip.com>
Date: Wed, 15 Dec 2021 13:01:05 +0200
Subject: [PATCH] dmaengine: at_xdmac: Start transfer for cyclic channels in
 issue_pending

commit e6af9b05bec63cd4d1de2a33968cd0be2a91282a upstream.

Cyclic channels must too call issue_pending in order to start a transfer.
Start the transfer in issue_pending regardless of the type of channel.
This wrongly worked before, because in the past the transfer was started
at tx_submit level when only a desc in the transfer list.

Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Change-Id: If1bf3e13329cebb9904ae40620f6cf2b7f06fe9f
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Mickael GARDET <m.gardet@overkiz.com>
---
 drivers/dma/at_xdmac.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index f63d141481a3..9aae6b3da356 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1726,11 +1726,13 @@ static irqreturn_t at_xdmac_interrupt(int irq, void *dev_id)
 static void at_xdmac_issue_pending(struct dma_chan *chan)
 {
 	struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
+	unsigned long flags;
 
 	dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
 
-	if (!at_xdmac_chan_is_cyclic(atchan))
-		at_xdmac_advance_work(atchan);
+	spin_lock_irqsave(&atchan->lock, flags);
+	at_xdmac_advance_work(atchan);
+	spin_unlock_irqrestore(&atchan->lock, flags);
 
 	return;
 }
-- 
2.35.1

Re: Atmel UART with dma enabled does not work on branch 5.4.Y from version 5.4.174.

[Greg KH]

On Fri, Feb 18, 2022 at 09:59:34AM +0100, Mickael GARDET wrote:
> Yes sorry,
> 
> enclosed signed patch.

That worked, now queued up, thanks!

greg k-h

Re: Atmel UART with dma enabled does not work on branch 5.4.Y from version 5.4.174.

[Mickael GARDET]

Thanks y'all for your help.

Mick G

Le 18/02/2022 à 10:41, Greg KH a écrit :
> On Fri, Feb 18, 2022 at 09:59:34AM +0100, Mickael GARDET wrote:
>> Yes sorry,
>>
>> enclosed signed patch.
> 
> That worked, now queued up, thanks!
> 
> greg k-h