Re: [PATCH] drm: gma500: fix logic error

From: Daniel Vetter
Date: Tue Sep 05 2017 - 07:08:56 EST


On Tue, Sep 05, 2017 at 09:47:26AM +0200, Arnd Bergmann wrote:
> gcc-8 points out a condition that almost certainly doesn't
> do what the author had in mind:
>
> drivers/gpu/drm/gma500/mdfld_intel_display.c: In function 'mdfldWaitForPipeEnable':
> drivers/gpu/drm/gma500/mdfld_intel_display.c:102:37: error: bitwise comparison always evaluates to false [-Werror=tautological-compare]
>
> This changes it to a simple bit mask operation to check
> whether the bit is set.
>
> Fixes: 026abc333205 ("gma500: initial medfield merge")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Applied to drm-misc, thanks.
-Daniel

> ---
> drivers/gpu/drm/gma500/mdfld_intel_display.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/gma500/mdfld_intel_display.c b/drivers/gpu/drm/gma500/mdfld_intel_display.c
> index 531e4450c000..5c066448be5b 100644
> --- a/drivers/gpu/drm/gma500/mdfld_intel_display.c
> +++ b/drivers/gpu/drm/gma500/mdfld_intel_display.c
> @@ -99,7 +99,7 @@ void mdfldWaitForPipeEnable(struct drm_device *dev, int pipe)
> /* Wait for for the pipe enable to take effect. */
> for (count = 0; count < COUNT_MAX; count++) {
> temp = REG_READ(map->conf);
> - if ((temp & PIPEACONF_PIPE_STATE) == 1)
> + if (temp & PIPEACONF_PIPE_STATE)
> break;
> }
> }
> --
> 2.9.0
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch