[PATCH v3] dmaengine: loongson: Remove the dev_dbg() output

[PATCH v3] dmaengine: loongson: Remove the dev_dbg() output

[Sebastian Andrzej Siewior]

The %pK format modifier was meant for /proc kind of output, not general
printk output. Since commit ad67b74d2469d ("printk: hash addresses
printed with %p") pointers are hashed by default and the behaviour can
be controller by `hash_pointers' boot argument.
The policy on %p is to not introduce new ones.

The output in loongson2_cmc_dma_issue_pending() is the only dev_dbg()
output in the driver and is only output once the transfer is started.
There is no output issued by the driver if the transfer is completed, if
a follow-up transfer is started or if any of the other callbacks (such
as loongson2_cmc_dma_tx_status()) are invoked. This output does not look
essential.

Instead removing just the %pK output, remove the complete dev_dbg()
output from the driver.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---

On 2026-09-18 16:44:59 [-0500], Frank Li wrote:
> 
> please careful,
> 
> remove whole dev_dbg() when vchan_issue_pending() failure.
> 
> commit messesge should show why it is okay to remove dev_dbg() here.

Is the arguing now reasonable?

> Frank

v2…v3: https://lore.kernel.org/all/20260918201714.eFNI3VMq@linutronix.de/
  - Reword part of the commit message.

v1…v2: https://lore.kernel.org/all/20260918103409.UV4g2ON7@linutronix.de/
  - Update subject line (it is removed, not replaced).

 drivers/dma/loongson/loongson2-apb-cmc-dma.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/dma/loongson/loongson2-apb-cmc-dma.c b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
index 1c9a542edc859..27f8f7a5738d9 100644
--- a/drivers/dma/loongson/loongson2-apb-cmc-dma.c
+++ b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
@@ -337,7 +337,6 @@ static void loongson2_cmc_dma_issue_pending(struct dma_chan *chan)
 	guard(spinlock_irqsave)(&lchan->vchan.lock);
 
 	if (vchan_issue_pending(&lchan->vchan) && !lchan->desc) {
-		dev_dbg(chan2dev(lchan), "vchan %pK: issued\n", &lchan->vchan);
 		loongson2_cmc_dma_start_transfer(lchan);
 	}
 }
-- 
2.55.0

Re: [PATCH v3] dmaengine: loongson: Remove the dev_dbg() output

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] dmaengine: loongson: unnecessary curly braces around single statement
--

commit 800bb056df0405c03d12921052d730f7cccef7be
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

dmaengine: loongson: Remove the dev_dbg() output

This commit removes the dev_dbg() output from
loongson2_cmc_dma_issue_pending() since the %pK format modifier is not
appropriate for general printk output. The debug statement was deemed
non-essential and is completely removed.

> diff --git a/drivers/dma/loongson/loongson2-apb-cmc-dma.c b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> index 1c9a542edc859..27f8f7a5738d9 100644
> --- a/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> +++ b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> @@ -337,7 +337,6 @@ static void loongson2_cmc_dma_issue_pending(struct dma_chan *chan)
>  	guard(spinlock_irqsave)(&lchan->vchan.lock);
>  
>  	if (vchan_issue_pending(&lchan->vchan) && !lchan->desc) {
> -		dev_dbg(chan2dev(lchan), "vchan %pK: issued\n", &lchan->vchan);
>  		loongson2_cmc_dma_start_transfer(lchan);
>  	}

[Severity: Low]
This isn't a bug, but with the removal of the dev_dbg() statement, this if
block now contains only a single statement. Should the curly braces be
removed to adhere to the kernel coding style guidelines?

>  }

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260921151312.I8Q8NLnx@linutronix.de?part=1

Re: [PATCH v3] dmaengine: loongson: Remove the dev_dbg() output

[Frank Li]

On Mon, Sep 21, 2026 at 03:16:14PM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Low] dmaengine: loongson: unnecessary curly braces around single statement
> --
>
> commit 800bb056df0405c03d12921052d730f7cccef7be
> Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
>
> dmaengine: loongson: Remove the dev_dbg() output
>
> This commit removes the dev_dbg() output from
> loongson2_cmc_dma_issue_pending() since the %pK format modifier is not
> appropriate for general printk output. The debug statement was deemed
> non-essential and is completely removed.
>
> > diff --git a/drivers/dma/loongson/loongson2-apb-cmc-dma.c b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> > index 1c9a542edc859..27f8f7a5738d9 100644
> > --- a/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> > +++ b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> > @@ -337,7 +337,6 @@ static void loongson2_cmc_dma_issue_pending(struct dma_chan *chan)
> >  	guard(spinlock_irqsave)(&lchan->vchan.lock);
> >
> >  	if (vchan_issue_pending(&lchan->vchan) && !lchan->desc) {
> > -		dev_dbg(chan2dev(lchan), "vchan %pK: issued\n", &lchan->vchan);
> >  		loongson2_cmc_dma_start_transfer(lchan);
> >  	}
>
> [Severity: Low]
> This isn't a bug, but with the removal of the dev_dbg() statement, this if
> block now contains only a single statement. Should the curly braces be
> removed to adhere to the kernel coding style guidelines?

Please fix this also.

Frank

>
> >  }
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260921151312.I8Q8NLnx@linutronix.de?part=1

Re: [PATCH v3] dmaengine: loongson: Remove the dev_dbg() output

[Frank Li]

On Mon, Sep 21, 2026 at 05:13:12PM +0200, Sebastian Andrzej Siewior wrote:
> The %pK format modifier was meant for /proc kind of output, not general
> printk output. Since commit ad67b74d2469d ("printk: hash addresses
> printed with %p") pointers are hashed by default and the behaviour can
> be controller by `hash_pointers' boot argument.
> The policy on %p is to not introduce new ones.
>
> The output in loongson2_cmc_dma_issue_pending() is the only dev_dbg()
> output in the driver and is only output once the transfer is started.
> There is no output issued by the driver if the transfer is completed, if
> a follow-up transfer is started or if any of the other callbacks (such
> as loongson2_cmc_dma_tx_status()) are invoked. This output does not look
> essential.
>
> Instead removing just the %pK output, remove the complete dev_dbg()
> output from the driver.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>


> On 2026-09-18 16:44:59 [-0500], Frank Li wrote:
> >
> > please careful,
> >
> > remove whole dev_dbg() when vchan_issue_pending() failure.
> >
> > commit messesge should show why it is okay to remove dev_dbg() here.
>
> Is the arguing now reasonable?
>
> > Frank
>
> v2…v3: https://lore.kernel.org/all/20260918201714.eFNI3VMq@linutronix.de/
>   - Reword part of the commit message.
>
> v1…v2: https://lore.kernel.org/all/20260918103409.UV4g2ON7@linutronix.de/
>   - Update subject line (it is removed, not replaced).
>
>  drivers/dma/loongson/loongson2-apb-cmc-dma.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/drivers/dma/loongson/loongson2-apb-cmc-dma.c b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> index 1c9a542edc859..27f8f7a5738d9 100644
> --- a/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> +++ b/drivers/dma/loongson/loongson2-apb-cmc-dma.c
> @@ -337,7 +337,6 @@ static void loongson2_cmc_dma_issue_pending(struct dma_chan *chan)
>  	guard(spinlock_irqsave)(&lchan->vchan.lock);
>
>  	if (vchan_issue_pending(&lchan->vchan) && !lchan->desc) {
> -		dev_dbg(chan2dev(lchan), "vchan %pK: issued\n", &lchan->vchan);
>  		loongson2_cmc_dma_start_transfer(lchan);
>  	}
>  }
> --
> 2.55.0
>