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* [PATCH] drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0)
@ 2017-02-07 13:51 Joonas Lahtinen
  2017-02-07 14:03 ` Chris Wilson
  2017-02-07 16:28 ` ✗ Fi.CI.BAT: failure for " Patchwork
  0 siblings, 2 replies; 4+ messages in thread
From: Joonas Lahtinen @ 2017-02-07 13:51 UTC (permalink / raw)
  To: Intel graphics driver community testing & development

"BIT(max) - 1" will overflow when max = 32, and GCC will complain.
We already have GENMASK for generating the mask, use it!

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_device_info.c | 2 +-
 drivers/gpu/drm/i915/intel_fbdev.c       | 2 +-
 drivers/gpu/drm/i915/intel_runtime_pm.c  | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
index fcf8181..1c06fbb 100644
--- a/drivers/gpu/drm/i915/intel_device_info.c
+++ b/drivers/gpu/drm/i915/intel_device_info.c
@@ -234,7 +234,7 @@ static void broadwell_sseu_info_init(struct drm_i915_private *dev_priv)
 	 * The subslice disable field is global, i.e. it applies
 	 * to each of the enabled slices.
 	 */
-	sseu->subslice_mask = BIT(ss_max) - 1;
+	sseu->subslice_mask = GENMASK(ss_max, 0);
 	sseu->subslice_mask &= ~((fuse2 & GEN8_F2_SS_DIS_MASK) >>
 				 GEN8_F2_SS_DIS_SHIFT);
 
diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index 1b8ba2e..1a0eeb9 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -371,7 +371,7 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 		return false;
 
 	memcpy(save_enabled, enabled, count);
-	mask = BIT(count) - 1;
+	mask = GENMASK(count, 0);
 	conn_configured = 0;
 retry:
 	for (i = 0; i < count; i++) {
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 66aa1bb..8258fd6 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -1249,7 +1249,7 @@ static void vlv_dpio_cmn_power_well_disable(struct drm_i915_private *dev_priv,
 	vlv_set_power_well(dev_priv, power_well, false);
 }
 
-#define POWER_DOMAIN_MASK (BIT(POWER_DOMAIN_NUM) - 1)
+#define POWER_DOMAIN_MASK (GENMASK(POWER_DOMAIN_NUM, 0))
 
 static struct i915_power_well *lookup_power_well(struct drm_i915_private *dev_priv,
 						 int power_well_id)
-- 
2.7.4

_______________________________________________
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Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH] drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0)
  2017-02-07 13:51 [PATCH] drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0) Joonas Lahtinen
@ 2017-02-07 14:03 ` Chris Wilson
  2017-02-07 14:38   ` Joonas Lahtinen
  2017-02-07 16:28 ` ✗ Fi.CI.BAT: failure for " Patchwork
  1 sibling, 1 reply; 4+ messages in thread
From: Chris Wilson @ 2017-02-07 14:03 UTC (permalink / raw)
  To: Joonas Lahtinen; +Cc: Intel graphics driver community testing & development

On Tue, Feb 07, 2017 at 03:51:41PM +0200, Joonas Lahtinen wrote:
> "BIT(max) - 1" will overflow when max = 32, and GCC will complain.
> We already have GENMASK for generating the mask, use it!
> 
> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/intel_device_info.c | 2 +-
>  drivers/gpu/drm/i915/intel_fbdev.c       | 2 +-
>  drivers/gpu/drm/i915/intel_runtime_pm.c  | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
> index fcf8181..1c06fbb 100644
> --- a/drivers/gpu/drm/i915/intel_device_info.c
> +++ b/drivers/gpu/drm/i915/intel_device_info.c
> @@ -234,7 +234,7 @@ static void broadwell_sseu_info_init(struct drm_i915_private *dev_priv)
>  	 * The subslice disable field is global, i.e. it applies
>  	 * to each of the enabled slices.
>  	 */
> -	sseu->subslice_mask = BIT(ss_max) - 1;
> +	sseu->subslice_mask = GENMASK(ss_max, 0);

Too simple!

	BUILD_BUG_ON(BIT(ss_max)-1 != GENMASK(ss_max, 0));

Needs to be GENMASK(ss_max - 1, 0); the high bit is inclusive.

Otherwise, the list matches up with a quick grep for BIT*(x)-1.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH] drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0)
  2017-02-07 14:03 ` Chris Wilson
@ 2017-02-07 14:38   ` Joonas Lahtinen
  0 siblings, 0 replies; 4+ messages in thread
From: Joonas Lahtinen @ 2017-02-07 14:38 UTC (permalink / raw)
  To: Chris Wilson; +Cc: Intel graphics driver community testing & development

On ti, 2017-02-07 at 14:03 +0000, Chris Wilson wrote:
> On Tue, Feb 07, 2017 at 03:51:41PM +0200, Joonas Lahtinen wrote:
> > 
> > "BIT(max) - 1" will overflow when max = 32, and GCC will complain.
> > We already have GENMASK for generating the mask, use it!
> > 
> > Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> > Cc: Chris Wilson <chris@chris-wilson.co.uk>
> > ---
> >  drivers/gpu/drm/i915/intel_device_info.c | 2 +-
> >  drivers/gpu/drm/i915/intel_fbdev.c       | 2 +-
> >  drivers/gpu/drm/i915/intel_runtime_pm.c  | 2 +-
> >  3 files changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
> > index fcf8181..1c06fbb 100644
> > --- a/drivers/gpu/drm/i915/intel_device_info.c
> > +++ b/drivers/gpu/drm/i915/intel_device_info.c
> > @@ -234,7 +234,7 @@ static void broadwell_sseu_info_init(struct drm_i915_private *dev_priv)
> > > >  	 * The subslice disable field is global, i.e. it applies
> > > >  	 * to each of the enabled slices.
> > > >  	 */
> > > > -	sseu->subslice_mask = BIT(ss_max) - 1;
> > > > +	sseu->subslice_mask = GENMASK(ss_max, 0);
> 
> Too simple!
> 
> 	BUILD_BUG_ON(BIT(ss_max)-1 != GENMASK(ss_max, 0));
> 
> Needs to be GENMASK(ss_max - 1, 0); the high bit is inclusive.
> 
> Otherwise, the list matches up with a quick grep for BIT*(x)-1.

Whoop, seem to have nucleared my kernel config. I think better check if
the same warning is triggered too, with GENMASK :)

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply	[flat|nested] 4+ messages in thread
* ✗ Fi.CI.BAT: failure for drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0)
  2017-02-07 13:51 [PATCH] drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0) Joonas Lahtinen
  2017-02-07 14:03 ` Chris Wilson
@ 2017-02-07 16:28 ` Patchwork
  1 sibling, 0 replies; 4+ messages in thread
From: Patchwork @ 2017-02-07 16:28 UTC (permalink / raw)
  To: Joonas Lahtinen; +Cc: intel-gfx

== Series Details ==

Series: drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0)
URL   : https://patchwork.freedesktop.org/series/19240/
State : failure

== Summary ==

Series 19240v1 drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0)
https://patchwork.freedesktop.org/api/1.0/series/19240/revisions/1/mbox/

Test core_auth:
        Subgroup basic-auth:
                pass       -> INCOMPLETE (fi-skl-6260u)
                pass       -> INCOMPLETE (fi-skl-6700hq)
                pass       -> INCOMPLETE (fi-ivb-3770)
                pass       -> INCOMPLETE (fi-bxt-j4205)
                pass       -> INCOMPLETE (fi-bxt-t5700)
                pass       -> INCOMPLETE (fi-byt-n2820)
                pass       -> INCOMPLETE (fi-kbl-7500u)
                pass       -> INCOMPLETE (fi-snb-2520m)
                pass       -> INCOMPLETE (fi-skl-6700k)
                pass       -> INCOMPLETE (fi-byt-j1900)
                pass       -> INCOMPLETE (fi-skl-6770hq)
                pass       -> INCOMPLETE (fi-hsw-4770)
                pass       -> INCOMPLETE (fi-ilk-650)
                pass       -> INCOMPLETE (fi-hsw-4770r)
                pass       -> INCOMPLETE (fi-snb-2600)
                pass       -> INCOMPLETE (fi-bsw-n3050)
                pass       -> INCOMPLETE (fi-ivb-3520m)
                pass       -> INCOMPLETE (fi-bdw-5557u)

fi-bdw-5557u     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-bsw-n3050     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-bxt-j4205     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-bxt-t5700     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-byt-j1900     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-byt-n2820     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-hsw-4770      total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-hsw-4770r     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-ilk-650       total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-ivb-3520m     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-ivb-3770      total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-kbl-7500u     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-skl-6260u     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-skl-6700hq    total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-skl-6700k     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-skl-6770hq    total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-snb-2520m     total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  
fi-snb-2600      total:1    pass:0    dwarn:0   dfail:0   fail:0   skip:0  

b8157792b685dfcc86fa7dc23d66d663ad6fb93f drm-tip: 2017y-02m-07d-14h-55m-05s UTC integration manifest
23cf9f6 drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0)

== Logs ==

For more details see: https://intel-gfx-ci.01.org/CI/Patchwork_3723/
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-02-07 16:28 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-02-07 13:51 [PATCH] drm/i915: Avoid BIT(max) - 1 and use GENMASK(max, 0) Joonas Lahtinen
2017-02-07 14:03 ` Chris Wilson
2017-02-07 14:38   ` Joonas Lahtinen
2017-02-07 16:28 ` ✗ Fi.CI.BAT: failure for " Patchwork

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