Re: [PATCH 5/5] spi: fix return value check in hspi_probe().
On Fri, Jan 11, 2013 at 03:02:02PM +, Grant Likely wrote: > On Thu, 3 Jan 2013 19:04:55 +0300, Dan Carpenter > wrote: > > On Sat, Dec 22, 2012 at 09:56:20AM +, Grant Likely wrote: > > > On Wed, 19 Dec 2012 19:39:14 +0300, Dan Carpenter > > > wrote: > > > > On Wed, Dec 19, 2012 at 03:11:54PM +, Grant Likely wrote: > > > > > On Tue, 11 Dec 2012 16:36:27 -0800 (PST), Kuninori Morimoto > > > > > wrote: > > > > > > > > > > > > Hi > > > > > > > > > > > > > According to its documentation, clk_get() returns a "valid > > > > > > > IS_ERR() condition > > > > > > > containing errno", so we should call IS_ERR() rather than a NULL > > > > > > > check. > > > > > > > > > > > > > > Signed-off-by: Cyril Roelandt > > > > > > > > > > > > Acked-by: Kuninori Morimoto > > > > > > > > > > Applied, thanks. > > > > > > > > In another thread, we were just talking about who clk_get() can > > > > return a NULL if !CONFIG_HAVE_CLK. That might change to match the > > > > documentation later... Not sure. > > > > > > So what is the solution here? Will the dummy clk_get() be changed, or is > > > there more work needed on the drivers? > > > > > > > This driver can't function without a clk. It should select that at > > build time instead of testing for it at probe. Just checking for > > IS_ERR() will NOT cause a NULL dereference so the patch is ok in > > that respect. I'm not sure if this can be build without > > CONFIG_HAVE_CLK. > > Your suggestion is to make this driver depend on CONFIG_HAVE_CLK? I'm > fine with that, but it doesn't sort out the core infrastructure question > about whether it is valid for the empty clk_get() to return NULL. Nor is > it a particularly sustainable solution (ie. if a large number of drivers > want to do the same thing). > We've spread this conversation out across several different threads. http://lists.infradead.org/pipermail/linux-arm-kernel/2013-January/139186.html Basically, drivers should use accessor functions which handle NULL pointers instead of dereferencing the pointer directly. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] spi: fix return value check in hspi_probe().
On Thu, 3 Jan 2013 19:04:55 +0300, Dan Carpenter wrote: > On Sat, Dec 22, 2012 at 09:56:20AM +, Grant Likely wrote: > > On Wed, 19 Dec 2012 19:39:14 +0300, Dan Carpenter > > wrote: > > > On Wed, Dec 19, 2012 at 03:11:54PM +, Grant Likely wrote: > > > > On Tue, 11 Dec 2012 16:36:27 -0800 (PST), Kuninori Morimoto > > > > wrote: > > > > > > > > > > Hi > > > > > > > > > > > According to its documentation, clk_get() returns a "valid IS_ERR() > > > > > > condition > > > > > > containing errno", so we should call IS_ERR() rather than a NULL > > > > > > check. > > > > > > > > > > > > Signed-off-by: Cyril Roelandt > > > > > > > > > > Acked-by: Kuninori Morimoto > > > > > > > > Applied, thanks. > > > > > > In another thread, we were just talking about who clk_get() can > > > return a NULL if !CONFIG_HAVE_CLK. That might change to match the > > > documentation later... Not sure. > > > > So what is the solution here? Will the dummy clk_get() be changed, or is > > there more work needed on the drivers? > > > > This driver can't function without a clk. It should select that at > build time instead of testing for it at probe. Just checking for > IS_ERR() will NOT cause a NULL dereference so the patch is ok in > that respect. I'm not sure if this can be build without > CONFIG_HAVE_CLK. Your suggestion is to make this driver depend on CONFIG_HAVE_CLK? I'm fine with that, but it doesn't sort out the core infrastructure question about whether it is valid for the empty clk_get() to return NULL. Nor is it a particularly sustainable solution (ie. if a large number of drivers want to do the same thing). g. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] spi: fix return value check in hspi_probe().
On Sat, Dec 22, 2012 at 09:56:20AM +, Grant Likely wrote: > On Wed, 19 Dec 2012 19:39:14 +0300, Dan Carpenter > wrote: > > On Wed, Dec 19, 2012 at 03:11:54PM +, Grant Likely wrote: > > > On Tue, 11 Dec 2012 16:36:27 -0800 (PST), Kuninori Morimoto > > > wrote: > > > > > > > > Hi > > > > > > > > > According to its documentation, clk_get() returns a "valid IS_ERR() > > > > > condition > > > > > containing errno", so we should call IS_ERR() rather than a NULL > > > > > check. > > > > > > > > > > Signed-off-by: Cyril Roelandt > > > > > > > > Acked-by: Kuninori Morimoto > > > > > > Applied, thanks. > > > > In another thread, we were just talking about who clk_get() can > > return a NULL if !CONFIG_HAVE_CLK. That might change to match the > > documentation later... Not sure. > > So what is the solution here? Will the dummy clk_get() be changed, or is > there more work needed on the drivers? > This driver can't function without a clk. It should select that at build time instead of testing for it at probe. Just checking for IS_ERR() will NOT cause a NULL dereference so the patch is ok in that respect. I'm not sure if this can be build without CONFIG_HAVE_CLK. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] spi: fix return value check in hspi_probe().
On Wed, 19 Dec 2012 19:39:14 +0300, Dan Carpenter wrote: > On Wed, Dec 19, 2012 at 03:11:54PM +, Grant Likely wrote: > > On Tue, 11 Dec 2012 16:36:27 -0800 (PST), Kuninori Morimoto > > wrote: > > > > > > Hi > > > > > > > According to its documentation, clk_get() returns a "valid IS_ERR() > > > > condition > > > > containing errno", so we should call IS_ERR() rather than a NULL check. > > > > > > > > Signed-off-by: Cyril Roelandt > > > > > > Acked-by: Kuninori Morimoto > > > > Applied, thanks. > > In another thread, we were just talking about who clk_get() can > return a NULL if !CONFIG_HAVE_CLK. That might change to match the > documentation later... Not sure. So what is the solution here? Will the dummy clk_get() be changed, or is there more work needed on the drivers? /me stifles a rant about the PTR_ERR pattern g. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] spi: fix return value check in hspi_probe().
On Wed, Dec 19, 2012 at 03:11:54PM +, Grant Likely wrote: > On Tue, 11 Dec 2012 16:36:27 -0800 (PST), Kuninori Morimoto > wrote: > > > > Hi > > > > > According to its documentation, clk_get() returns a "valid IS_ERR() > > > condition > > > containing errno", so we should call IS_ERR() rather than a NULL check. > > > > > > Signed-off-by: Cyril Roelandt > > > > Acked-by: Kuninori Morimoto > > Applied, thanks. In another thread, we were just talking about who clk_get() can return a NULL if !CONFIG_HAVE_CLK. That might change to match the documentation later... Not sure. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] spi: fix return value check in hspi_probe().
On Tue, 11 Dec 2012 16:36:27 -0800 (PST), Kuninori Morimoto wrote: > > Hi > > > According to its documentation, clk_get() returns a "valid IS_ERR() > > condition > > containing errno", so we should call IS_ERR() rather than a NULL check. > > > > Signed-off-by: Cyril Roelandt > > Acked-by: Kuninori Morimoto Applied, thanks. g. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] spi: fix return value check in hspi_probe().
Hi
> According to its documentation, clk_get() returns a "valid IS_ERR() condition
> containing errno", so we should call IS_ERR() rather than a NULL check.
>
> Signed-off-by: Cyril Roelandt
Acked-by: Kuninori Morimoto
> ---
> drivers/spi/spi-sh-hspi.c |2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-sh-hspi.c b/drivers/spi/spi-sh-hspi.c
> index 32f7b55..60cfae5 100644
> --- a/drivers/spi/spi-sh-hspi.c
> +++ b/drivers/spi/spi-sh-hspi.c
> @@ -290,7 +290,7 @@ static int hspi_probe(struct platform_device *pdev)
> }
>
> clk = clk_get(NULL, "shyway_clk");
> - if (!clk) {
> + if (IS_ERR(clk)) {
> dev_err(&pdev->dev, "shyway_clk is required\n");
> ret = -EINVAL;
> goto error0;
> --
> 1.7.10.4
>
>
> --
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Best regards
---
Kuninori Morimoto
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[PATCH 5/5] spi: fix return value check in hspi_probe().
According to its documentation, clk_get() returns a "valid IS_ERR() condition
containing errno", so we should call IS_ERR() rather than a NULL check.
Signed-off-by: Cyril Roelandt
---
drivers/spi/spi-sh-hspi.c |2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/spi/spi-sh-hspi.c b/drivers/spi/spi-sh-hspi.c
index 32f7b55..60cfae5 100644
--- a/drivers/spi/spi-sh-hspi.c
+++ b/drivers/spi/spi-sh-hspi.c
@@ -290,7 +290,7 @@ static int hspi_probe(struct platform_device *pdev)
}
clk = clk_get(NULL, "shyway_clk");
- if (!clk) {
+ if (IS_ERR(clk)) {
dev_err(&pdev->dev, "shyway_clk is required\n");
ret = -EINVAL;
goto error0;
--
1.7.10.4
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