diff mbox series

dmaengine: qcom_hidma: Simplify error handling path in hidma_probe

Message ID 20200427111043.70218-1-christophe.jaillet@wanadoo.fr (mailing list archive)
State Mainlined
Commit 920c5974f0d3aff91b5751e7568b54752fb5d6da
Headers show
Series dmaengine: qcom_hidma: Simplify error handling path in hidma_probe | expand

Commit Message

Christophe JAILLET April 27, 2020, 11:10 a.m. UTC
There is no need to call 'hidma_debug_uninit()' in the error handling
path. 'hidma_debug_init()' has not been called yet.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/dma/qcom/hidma.c | 1 -
 1 file changed, 1 deletion(-)

Comments

Vinod Koul April 27, 2020, 4:08 p.m. UTC | #1
On 27-04-20, 13:10, Christophe JAILLET wrote:
> There is no need to call 'hidma_debug_uninit()' in the error handling
> path. 'hidma_debug_init()' has not been called yet.

Applied, thanks
Dan Carpenter April 28, 2020, 12:54 p.m. UTC | #2
On Mon, Apr 27, 2020 at 01:10:43PM +0200, Christophe JAILLET wrote:
> There is no need to call 'hidma_debug_uninit()' in the error handling
> path. 'hidma_debug_init()' has not been called yet.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
>  drivers/dma/qcom/hidma.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c
> index 411f91fde734..87490e125bc3 100644
> --- a/drivers/dma/qcom/hidma.c
> +++ b/drivers/dma/qcom/hidma.c
> @@ -897,7 +897,6 @@ static int hidma_probe(struct platform_device *pdev)
>  	if (msi)
            ^^^
This test doesn't work.  It will call free hidma_free_msis() if the
hidma_request_msi() call fails.  We should do:

	if (msi) {
		rc = hidma_request_msi(dmadev, pdev);
		msi = false;
	}

	if (!msi) {
		hidma_ll_setup_irq(dmadev->lldev, false);
		rc = devm_request_irq(&pdev->dev, chirq, hidma_chirq_handler,
				      0, "qcom-hidma", dmadev->lldev);
		if (rc)
			goto uninit;
	}


>  		hidma_free_msis(dmadev);
>  
> -	hidma_debug_uninit(dmadev);
>  	hidma_ll_uninit(dmadev->lldev);
>  dmafree:
>  	if (dmadev)
            ^^^^^^
This test isn't necessary and should be deleted.

regards,
dan carpenter
Sinan Kaya April 28, 2020, 4:01 p.m. UTC | #3
On 4/28/2020 8:54 AM, Dan Carpenter wrote:
>> @@ -897,7 +897,6 @@ static int hidma_probe(struct platform_device *pdev)
>>  	if (msi)
>             ^^^
> This test doesn't work.  It will call free hidma_free_msis() if the
> hidma_request_msi() call fails.  We should do:
> 
> 	if (msi) {
> 		rc = hidma_request_msi(dmadev, pdev);
> 		msi = false;
> 	}
> 
> 	if (!msi) {
> 		hidma_ll_setup_irq(dmadev->lldev, false);
> 		rc = devm_request_irq(&pdev->dev, chirq, hidma_chirq_handler,
> 				      0, "qcom-hidma", dmadev->lldev);
> 		if (rc)
> 			goto uninit;
> 	}
> 
> 

Let me clarify how this works. MSI capability is not present on all
platforms. Therefore, this is detected by an ACPI/DTS parameter called
HIDMA_MSI_CAP.

msi = hidma_test_capability(&pdev->dev, HIDMA_MSI_CAP);

Therefore,

1. Code will request MSI capability if it is present.
2. Code will fallback to plain IRQ, if MSI allocation also fails.

I hope this helps.

We need both #1 and #2 to be supported.
Dan Carpenter April 28, 2020, 5:21 p.m. UTC | #4
I apologize, I wrote my code hurriedly and did no explain the bug well.
I understood what the code is doing, but my fix was missing an if
condition.

On Tue, Apr 28, 2020 at 12:01:15PM -0400, Sinan Kaya wrote:
> On 4/28/2020 8:54 AM, Dan Carpenter wrote:
> >> @@ -897,7 +897,6 @@ static int hidma_probe(struct platform_device *pdev)
> >>  	if (msi)
> >             ^^^
> > This test doesn't work.  It will call free hidma_free_msis() if the
> > hidma_request_msi() call fails.  We should do:
> > 
> > 	if (msi) {
> > 		rc = hidma_request_msi(dmadev, pdev);
> > 		msi = false;

What I meant to say here was:

	if (msi) {
		rc = hidma_request_msi(dmadev, pdev);
		if (rc)
			msi = false;

Otherwise we end up checking freeing the msi in the error handling
code when we did not take it.

Hopefully, that clears things up?

regards,
dan carpenter
Sinan Kaya April 28, 2020, 8:29 p.m. UTC | #5
On 4/28/2020 1:21 PM, Dan Carpenter wrote:
> What I meant to say here was:
> 
> 	if (msi) {
> 		rc = hidma_request_msi(dmadev, pdev);
> 		if (rc)
> 			msi = false;
> 
> Otherwise we end up checking freeing the msi in the error handling
> code when we did not take it.
> 
> Hopefully, that clears things up?

Yes, that works. However, I'd rather use a different flag for this
in order not to mix the meaning of msi capability vs. msi allocation
failure.
diff mbox series

Patch

diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c
index 411f91fde734..87490e125bc3 100644
--- a/drivers/dma/qcom/hidma.c
+++ b/drivers/dma/qcom/hidma.c
@@ -897,7 +897,6 @@  static int hidma_probe(struct platform_device *pdev)
 	if (msi)
 		hidma_free_msis(dmadev);
 
-	hidma_debug_uninit(dmadev);
 	hidma_ll_uninit(dmadev->lldev);
 dmafree:
 	if (dmadev)