spi: sifive: check return value for platform_get_resource()
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Message ID 20190917085627.4562-1-mail@aurabindo.in
State New
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Series
  • spi: sifive: check return value for platform_get_resource()
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Commit Message

Aurabindo Jayamohanan Sept. 17, 2019, 9:12 a.m. UTC
platform_get_resource() may return NULL. If it is so, return -ENXIO

Signed-off-by: Aurabindo Jayamohanan <mail@aurabindo.in>
---
 drivers/spi/spi-sifive.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Paul Walmsley Sept. 17, 2019, 9:18 a.m. UTC | #1
On Tue, 17 Sep 2019, Aurabindo Jayamohanan wrote:

> platform_get_resource() may return NULL. If it is so, return -ENXIO
> 
> Signed-off-by: Aurabindo Jayamohanan <mail@aurabindo.in>

Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com>


- Paul
Baolin Wang Sept. 17, 2019, 9:23 a.m. UTC | #2
On Tue, 17 Sep 2019 at 17:12, Aurabindo Jayamohanan <mail@aurabindo.in> wrote:
>
> platform_get_resource() may return NULL. If it is so, return -ENXIO
>
> Signed-off-by: Aurabindo Jayamohanan <mail@aurabindo.in>
> ---
>  drivers/spi/spi-sifive.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
> index 93ec2c6cdbfd..67485067a694 100644
> --- a/drivers/spi/spi-sifive.c
> +++ b/drivers/spi/spi-sifive.c
> @@ -308,6 +308,12 @@ static int sifive_spi_probe(struct platform_device *pdev)
>         platform_set_drvdata(pdev, master);
>
>         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       if (!res) {
> +               dev_err(&pdev->dev, "no IOMEM resource found\n");
> +               ret = -ENXIO;
> +               goto put_master;
> +       }

Seems unnecessary, the devm_ioremap_resource() already validated if
the resource is available.
Aurabindo Jayamohanan Sept. 17, 2019, 9:58 a.m. UTC | #3
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, September 17, 2019 2:53 PM, Baolin Wang <baolin.wang@linaro.org> wrote:

> On Tue, 17 Sep 2019 at 17:12, Aurabindo Jayamohanan mail@aurabindo.in wrote:
>
> > platform_get_resource() may return NULL. If it is so, return -ENXIO
> >
> > Signed-off-by: Aurabindo Jayamohanan mail@aurabindo.in
> >
> > -------------------------------------------------------
> >
> > drivers/spi/spi-sifive.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> > diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
> > index 93ec2c6cdbfd..67485067a694 100644
> > --- a/drivers/spi/spi-sifive.c
> > +++ b/drivers/spi/spi-sifive.c
> > @@ -308,6 +308,12 @@ static int sifive_spi_probe(struct platform_device *pdev)
> > platform_set_drvdata(pdev, master);
> >
> >         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >
> >
> > -         if (!res) {
> >
> >
> > -                 dev_err(&pdev->dev, "no IOMEM resource found\\n");
> >
> >
> > -                 ret = -ENXIO;
> >
> >
> > -                 goto put_master;
> >
> >
> > -         }
> >
> >
>
> Seems unnecessary, the devm_ioremap_resource() already validated if
> the resource is available.
>

Okay, thanks for the headsup
Paul Walmsley Sept. 17, 2019, 12:15 p.m. UTC | #4
On Tue, 17 Sep 2019, Baolin Wang wrote:

> On Tue, 17 Sep 2019 at 17:12, Aurabindo Jayamohanan <mail@aurabindo.in> wrote:
> >
> > platform_get_resource() may return NULL. If it is so, return -ENXIO
> >
> > Signed-off-by: Aurabindo Jayamohanan <mail@aurabindo.in>
> > ---
> >  drivers/spi/spi-sifive.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
> > index 93ec2c6cdbfd..67485067a694 100644
> > --- a/drivers/spi/spi-sifive.c
> > +++ b/drivers/spi/spi-sifive.c
> > @@ -308,6 +308,12 @@ static int sifive_spi_probe(struct platform_device *pdev)
> >         platform_set_drvdata(pdev, master);
> >
> >         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +       if (!res) {
> > +               dev_err(&pdev->dev, "no IOMEM resource found\n");
> > +               ret = -ENXIO;
> > +               goto put_master;
> > +       }
> 
> Seems unnecessary, the devm_ioremap_resource() already validated if
> the resource is available.

Just doublechecked lib/devres.c and I agree with you.

Aurobindo, is this a patch for a real problem that you've encountered?


- Paul
Geert Uytterhoeven Sept. 17, 2019, 1:07 p.m. UTC | #5
Hi Paul,

On Tue, Sep 17, 2019 at 2:16 PM Paul Walmsley <paul.walmsley@sifive.com> wrote:
> On Tue, 17 Sep 2019, Baolin Wang wrote:
> > On Tue, 17 Sep 2019 at 17:12, Aurabindo Jayamohanan <mail@aurabindo.in> wrote:
> > > platform_get_resource() may return NULL. If it is so, return -ENXIO
> > >
> > > Signed-off-by: Aurabindo Jayamohanan <mail@aurabindo.in>
> > > ---
> > >  drivers/spi/spi-sifive.c | 6 ++++++
> > >  1 file changed, 6 insertions(+)
> > >
> > > diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
> > > index 93ec2c6cdbfd..67485067a694 100644
> > > --- a/drivers/spi/spi-sifive.c
> > > +++ b/drivers/spi/spi-sifive.c
> > > @@ -308,6 +308,12 @@ static int sifive_spi_probe(struct platform_device *pdev)
> > >         platform_set_drvdata(pdev, master);
> > >
> > >         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > +       if (!res) {
> > > +               dev_err(&pdev->dev, "no IOMEM resource found\n");
> > > +               ret = -ENXIO;
> > > +               goto put_master;
> > > +       }
> >
> > Seems unnecessary, the devm_ioremap_resource() already validated if
> > the resource is available.
>
> Just doublechecked lib/devres.c and I agree with you.
>
> Aurobindo, is this a patch for a real problem that you've encountered?

Probably not.

The sequence can be replaced by a single call to
devm_platform_ioremap_resource(), which BTW also doesn't check the
intermediate result, as that's unneeded.

Gr{oetje,eeting}s,

                        Geert
Aurabindo Jayamohanan Sept. 17, 2019, 2:06 p.m. UTC | #6
Hi Paul,

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, September 17, 2019 5:45 PM, Paul Walmsley <paul.walmsley@sifive.com> wrote:

> On Tue, 17 Sep 2019, Baolin Wang wrote:
>
> > On Tue, 17 Sep 2019 at 17:12, Aurabindo Jayamohanan mail@aurabindo.in wrote:
> >
> > > platform_get_resource() may return NULL. If it is so, return -ENXIO
> > >
> > > Signed-off-by: Aurabindo Jayamohanan mail@aurabindo.in
> > >
> > > -------------------------------------------------------
> > >
> > > drivers/spi/spi-sifive.c | 6 ++++++
> > > 1 file changed, 6 insertions(+)
> > > diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
> > > index 93ec2c6cdbfd..67485067a694 100644
> > > --- a/drivers/spi/spi-sifive.c
> > > +++ b/drivers/spi/spi-sifive.c
> > > @@ -308,6 +308,12 @@ static int sifive_spi_probe(struct platform_device *pdev)
> > > platform_set_drvdata(pdev, master);
> > >
> > >         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > >
> > >
> > > -         if (!res) {
> > >
> > >
> > > -                 dev_err(&pdev->dev, "no IOMEM resource found\\n");
> > >
> > >
> > > -                 ret = -ENXIO;
> > >
> > >
> > > -                 goto put_master;
> > >
> > >
> > > -         }
> > >
> > >
> >
> > Seems unnecessary, the devm_ioremap_resource() already validated if
> > the resource is available.
>
> Just doublechecked lib/devres.c and I agree with you.
>
> Aurobindo, is this a patch for a real problem that you've encountered?
>
> -   Paul

Geert is right. I was just breezing through the source and found it odd since
I noticed other instances checking for return value. Apparently none of those
use the managed api.

If you didnt already do Geert's suggestion, here is a patch:
Paul Walmsley Sept. 17, 2019, 2:11 p.m. UTC | #7
Aurobindo, 

On Tue, 17 Sep 2019, Aurabindo Jayamohanan wrote:

> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> On Tuesday, September 17, 2019 5:45 PM, Paul Walmsley <paul.walmsley@sifive.com> wrote:
> 
> > On Tue, 17 Sep 2019, Baolin Wang wrote:
> >
> > > On Tue, 17 Sep 2019 at 17:12, Aurabindo Jayamohanan mail@aurabindo.in wrote:
> > >
> > > > platform_get_resource() may return NULL. If it is so, return -ENXIO
> > > >
> > > > Signed-off-by: Aurabindo Jayamohanan mail@aurabindo.in
> > > >
> > > > -------------------------------------------------------
> > > >
> > > > drivers/spi/spi-sifive.c | 6 ++++++
> > > > 1 file changed, 6 insertions(+)
> > > > diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
> > > > index 93ec2c6cdbfd..67485067a694 100644
> > > > --- a/drivers/spi/spi-sifive.c
> > > > +++ b/drivers/spi/spi-sifive.c
> > > > @@ -308,6 +308,12 @@ static int sifive_spi_probe(struct platform_device *pdev)
> > > > platform_set_drvdata(pdev, master);
> > > >
> > > >         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > >
> > > >
> > > > -         if (!res) {
> > > >
> > > >
> > > > -                 dev_err(&pdev->dev, "no IOMEM resource found\\n");
> > > >
> > > >
> > > > -                 ret = -ENXIO;
> > > >
> > > >
> > > > -                 goto put_master;
> > > >
> > > >
> > > > -         }
> > > >
> > > >
> > >
> > > Seems unnecessary, the devm_ioremap_resource() already validated if
> > > the resource is available.
> >
> > Just doublechecked lib/devres.c and I agree with you.
> >
> > Aurobindo, is this a patch for a real problem that you've encountered?
> >
> > -   Paul
> 
> Geert is right. I was just breezing through the source and found it odd since
> I noticed other instances checking for return value. Apparently none of those
> use the managed api.
> 
> If you didnt already do Geert's suggestion,

Mark Brown is the maintainer, so he'd be the one to apply anything 
touching these drivers.

> here is a patch:

Could you please send this as a separate E-mail?

> ____
> 
> spi: sifive: use device managed api to get plaform resource

"platform resource"

> 
> calls to devm_ioremap_resource() preceeded by platform_get_resource()

"Calls"

"preceded"

> may be replaced by devm_platform_ioremap_resource().

Please explain why.  In this case "removing boilerplate from the code" 
seems like a reasonable explanation.

> 
> Signed-off-by: Aurabindo Jayamohanan <mail@aurabindo.in>
> ---
>  drivers/spi/spi-sifive.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
> index 93ec2c6cdbfd..c0925aa98aad 100644
> --- a/drivers/spi/spi-sifive.c
> +++ b/drivers/spi/spi-sifive.c
> @@ -292,7 +292,6 @@ sifive_spi_transfer_one(struct spi_master *master, struct spi_device *device,
>  static int sifive_spi_probe(struct platform_device *pdev)
>  {
>  	struct sifive_spi *spi;
> -	struct resource *res;
>  	int ret, irq, num_cs;
>  	u32 cs_bits, max_bits_per_word;
>  	struct spi_master *master;
> @@ -307,8 +306,7 @@ static int sifive_spi_probe(struct platform_device *pdev)
>  	init_completion(&spi->done);
>  	platform_set_drvdata(pdev, master);
> 
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	spi->regs = devm_ioremap_resource(&pdev->dev, res);
> +	spi->regs = devm_platform_ioremap_resource(pdev, 0);
>  	if (IS_ERR(spi->regs)) {
>  		ret = PTR_ERR(spi->regs);
>  		goto put_master;
> --
> 2.23.0
> 


- Paul
Paul Walmsley Sept. 17, 2019, 3:21 p.m. UTC | #8
I just recalled that YueHaibing already posted a patch to do this:

https://lore.kernel.org/linux-riscv/alpine.DEB.2.21.9999.1909041520130.13502@viisi.sifive.com/


- Paul
Aurabindo Jayamohanan Sept. 17, 2019, 5:13 p.m. UTC | #9
Hi Paul,

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, September 17, 2019 8:51 PM, Paul Walmsley <paul.walmsley@sifive.com> wrote:

>
>
> I just recalled that YueHaibing already posted a patch to do this:
>
> https://lore.kernel.org/linux-riscv/alpine.DEB.2.21.9999.1909041520130.13502@viisi.sifive.com/
>

Ah, sorry for the noise.

Patch
diff mbox series

diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
index 93ec2c6cdbfd..67485067a694 100644
--- a/drivers/spi/spi-sifive.c
+++ b/drivers/spi/spi-sifive.c
@@ -308,6 +308,12 @@  static int sifive_spi_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, master);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "no IOMEM resource found\n");
+		ret = -ENXIO;
+		goto put_master;
+	}
+
 	spi->regs = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(spi->regs)) {
 		ret = PTR_ERR(spi->regs);