[PATCH] i2c: rcar: add IRQ check

[PATCH] i2c: rcar: add IRQ check

[Sergey Shtylyov]

The driver neglects to check the result of platform_get_irq()'s call and
blithely passes the negative error codes to devm_request_irq() (which
takes *unsigned* IRQ #), causing it to fail with -EINVAL, overriding
an original error code.  Stop calling devm_request_irq() with the
invalid IRQ #s.

Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>

---
 drivers/i2c/busses/i2c-rcar.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux/drivers/i2c/busses/i2c-rcar.c
===================================================================
--- linux.orig/drivers/i2c/busses/i2c-rcar.c
+++ linux/drivers/i2c/busses/i2c-rcar.c
@@ -1027,7 +1027,9 @@ static int rcar_i2c_probe(struct platfor
 	if (of_property_read_bool(dev->of_node, "smbus"))
 		priv->flags |= ID_P_HOST_NOTIFY;
 
-	priv->irq = platform_get_irq(pdev, 0);
+	priv->irq = ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		goto out_pm_disable;
 	ret = devm_request_irq(dev, priv->irq, irqhandler, irqflags, dev_name(dev), priv);
 	if (ret < 0) {
 		dev_err(dev, "cannot get irq %d\n", priv->irq);

Re: [PATCH] i2c: rcar: add IRQ check

[Sergey Shtylyov]

On 4/4/21 8:52 PM, Sergey Shtylyov wrote:

> The driver neglects to check the result of platform_get_irq()'s call and
> blithely passes the negative error codes to devm_request_irq() (which
> takes *unsigned* IRQ #), causing it to fail with -EINVAL, overriding
> an original error code.  Stop calling devm_request_irq() with the
> invalid IRQ #s.
> 
> Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver")
> Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>

   Sorry, forgot to mention that this patch is against the 'master' branch of
Wolfram's 'linux.git' repo...

MBR, Sergey

Re: [PATCH] i2c: rcar: add IRQ check

[Geert Uytterhoeven]

On Sun, Apr 4, 2021 at 7:53 PM Sergey Shtylyov <s.shtylyov@omprussia.ru> wrote:
> The driver neglects to check the result of platform_get_irq()'s call and
> blithely passes the negative error codes to devm_request_irq() (which
> takes *unsigned* IRQ #), causing it to fail with -EINVAL, overriding
> an original error code.  Stop calling devm_request_irq() with the
> invalid IRQ #s.
>
> Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver")
> Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] i2c: rcar: add IRQ check

[Wolfram Sang]

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> +	priv->irq = ret = platform_get_irq(pdev, 0);

Please no double assignments. Otherwise good catch!


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Re: [PATCH] i2c: rcar: add IRQ check

[Sergey Shtylyov]

On 4/9/21 12:04 AM, Wolfram Sang wrote:

>> +	priv->irq = ret = platform_get_irq(pdev, 0);
> 
> Please no double assignments. Otherwise good catch!

   OK, I'll come back with 5 more patches for the similar problems. :-)

MBR, Sergei