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| Started by | Arnd Bergmann <arnd@arndb.de> |
|---|---|
| First post | 2017-09-06 15:20 +0200 |
| Last post | 2017-09-08 08:40 +0200 |
| Articles | 3 — 3 participants |
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[PATCH] [RESEND] drm/stm: fix warning about multiplication in condition Arnd Bergmann <arnd@arndb.de> - 2017-09-06 15:20 +0200
Re: [PATCH] [RESEND] drm/stm: fix warning about multiplication in condition Archit Taneja <architt@codeaurora.org> - 2017-09-07 07:40 +0200
Re: [PATCH] [RESEND] drm/stm: fix warning about multiplication in condition Daniel Vetter <daniel@ffwll.ch> - 2017-09-08 08:40 +0200
| From | Arnd Bergmann <arnd@arndb.de> |
|---|---|
| Date | 2017-09-06 15:20 +0200 |
| Subject | [PATCH] [RESEND] drm/stm: fix warning about multiplication in condition |
| Message-ID | <umIpj-2iw-5@gated-at.bofh.it> |
gcc-7 complains about multiplying within a condition being
suspicious:
drivers/gpu/drm/stm/dw_mipi_dsi-stm.c: In function 'dsi_pll_get_clkout_khz':
drivers/gpu/drm/stm/dw_mipi_dsi-stm.c:117:10: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]
The code here is correct, but can be easily rephrased to make
that more obvious. I also swap out the error handling and the normal
code path for clarity.
Fixes: b0f09a3c69d9 ("drm/stm: Add STM32 DSI controller driver")
Acked-by: Philippe Cornu <philippe.cornu@st.com>
Tested-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
Originally sent on July 25, but never made it into linux-next.
The warning is currently disabled in mainline, but this seems
to be a legitimate instance, and we may want to turn it back
on in the future.
---
drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
index 568c5d0461ea..e5b6310240fe 100644
--- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
+++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
@@ -113,11 +113,13 @@ static enum dsi_color dsi_color_from_mipi(enum mipi_dsi_pixel_format fmt)
static int dsi_pll_get_clkout_khz(int clkin_khz, int idf, int ndiv, int odf)
{
+ int divisor = idf * odf;
+
/* prevent from division by 0 */
- if (idf * odf)
- return DIV_ROUND_CLOSEST(clkin_khz * ndiv, idf * odf);
+ if (!divisor)
+ return 0;
- return 0;
+ return DIV_ROUND_CLOSEST(clkin_khz * ndiv, divisor);
}
static int dsi_pll_get_params(int clkin_khz, int clkout_khz,
--
2.9.0
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| From | Archit Taneja <architt@codeaurora.org> |
|---|---|
| Date | 2017-09-07 07:40 +0200 |
| Subject | Re: [PATCH] [RESEND] drm/stm: fix warning about multiplication in condition |
| Message-ID | <umXHH-3QW-1@gated-at.bofh.it> |
| In reply to | #1727444 |
Hi Benjamin,
This should be pushed to drm-misc by you, right?
Thanks,
Archit
On 09/06/2017 06:43 PM, Arnd Bergmann wrote:
> gcc-7 complains about multiplying within a condition being
> suspicious:
>
> drivers/gpu/drm/stm/dw_mipi_dsi-stm.c: In function 'dsi_pll_get_clkout_khz':
> drivers/gpu/drm/stm/dw_mipi_dsi-stm.c:117:10: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]
>
> The code here is correct, but can be easily rephrased to make
> that more obvious. I also swap out the error handling and the normal
> code path for clarity.
>
> Fixes: b0f09a3c69d9 ("drm/stm: Add STM32 DSI controller driver")
> Acked-by: Philippe Cornu <philippe.cornu@st.com>
> Tested-by: Philippe Cornu <philippe.cornu@st.com>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> Originally sent on July 25, but never made it into linux-next.
> The warning is currently disabled in mainline, but this seems
> to be a legitimate instance, and we may want to turn it back
> on in the future.
> ---
> drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> index 568c5d0461ea..e5b6310240fe 100644
> --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> @@ -113,11 +113,13 @@ static enum dsi_color dsi_color_from_mipi(enum mipi_dsi_pixel_format fmt)
>
> static int dsi_pll_get_clkout_khz(int clkin_khz, int idf, int ndiv, int odf)
> {
> + int divisor = idf * odf;
> +
> /* prevent from division by 0 */
> - if (idf * odf)
> - return DIV_ROUND_CLOSEST(clkin_khz * ndiv, idf * odf);
> + if (!divisor)
> + return 0;
>
> - return 0;
> + return DIV_ROUND_CLOSEST(clkin_khz * ndiv, divisor);
> }
>
> static int dsi_pll_get_params(int clkin_khz, int clkout_khz,
>
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
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| From | Daniel Vetter <daniel@ffwll.ch> |
|---|---|
| Date | 2017-09-08 08:40 +0200 |
| Subject | Re: [PATCH] [RESEND] drm/stm: fix warning about multiplication in condition |
| Message-ID | <unl7j-327-1@gated-at.bofh.it> |
| In reply to | #1727916 |
On Thu, Sep 07, 2017 at 10:59:49AM +0530, Archit Taneja wrote:
> Hi Benjamin,
>
> This should be pushed to drm-misc by you, right?
I applied it. I guess Philippe Cornu should also become drm-misc committer
instead of just acking a patch and hoping fairies will pick it up.
-Daniel
>
> Thanks,
> Archit
>
> On 09/06/2017 06:43 PM, Arnd Bergmann wrote:
> > gcc-7 complains about multiplying within a condition being
> > suspicious:
> >
> > drivers/gpu/drm/stm/dw_mipi_dsi-stm.c: In function 'dsi_pll_get_clkout_khz':
> > drivers/gpu/drm/stm/dw_mipi_dsi-stm.c:117:10: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context]
> >
> > The code here is correct, but can be easily rephrased to make
> > that more obvious. I also swap out the error handling and the normal
> > code path for clarity.
> >
> > Fixes: b0f09a3c69d9 ("drm/stm: Add STM32 DSI controller driver")
> > Acked-by: Philippe Cornu <philippe.cornu@st.com>
> > Tested-by: Philippe Cornu <philippe.cornu@st.com>
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > ---
> > Originally sent on July 25, but never made it into linux-next.
> > The warning is currently disabled in mainline, but this seems
> > to be a legitimate instance, and we may want to turn it back
> > on in the future.
> > ---
> > drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 8 +++++---
> > 1 file changed, 5 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> > index 568c5d0461ea..e5b6310240fe 100644
> > --- a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> > +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c
> > @@ -113,11 +113,13 @@ static enum dsi_color dsi_color_from_mipi(enum mipi_dsi_pixel_format fmt)
> > static int dsi_pll_get_clkout_khz(int clkin_khz, int idf, int ndiv, int odf)
> > {
> > + int divisor = idf * odf;
> > +
> > /* prevent from division by 0 */
> > - if (idf * odf)
> > - return DIV_ROUND_CLOSEST(clkin_khz * ndiv, idf * odf);
> > + if (!divisor)
> > + return 0;
> > - return 0;
> > + return DIV_ROUND_CLOSEST(clkin_khz * ndiv, divisor);
> > }
> > static int dsi_pll_get_params(int clkin_khz, int clkout_khz,
> >
>
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> a Linux Foundation Collaborative Project
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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