Re: [Intel-gfx] [PATCH] drm/i915: Don't query PCODE RC6VIDS on platforms not supporting it
On Mon, Feb 12, 2018 at 12:33:57PM +0200, Jani Nikula wrote:
> On Thu, 08 Feb 2018, Imre Deak wrote:
> > On BXT/GLK GEN6_PCODE_READ_RC6VIDS fails with
> > MAILBOX_P24C_CC_ILLEGAL_CMD, so don't try to do the query on these
> > platforms. Do it only on SNB, IVB and HSW, where we use this command
> > anyway for RC6 enabling.
> >
> > Based on my tests the command also succeeds on all LLC platforms, but
> > it's not clear if it's really supported on those (it returns 0 aka 245mv
> > for all RC6 states everywhere except on SNB). BSpec lists the command as
> > supported on SKL+ (see P24C_PCODE_MAILBOX_INTERFACE) but that's clearly
> > incorrect, since on SKL/KBL the same command ID is used for
> > SKL_PCODE_LOAD_HDCP_KEYS. Since the command fails on BXT/GLK, the BSpec
> > command list is also incorrect for those platforms (see
> > P_CR_P24C_PCODE_MAILBOX_INTERFACE_0_2_0_GTTMMADR).
> >
> > I filed a request to update that info in Bspec, but for now let's
> > assume a minimal set of platforms where the command is supported.
> >
> > Reference: https://bugs.freedesktop.org/show_bug.cgi?id=103337
>
> If the patch fixes the bug, please use Bugzilla:.
>
> If the patch is related to the bug, please use References:.
It fixes a bug reported in that bug, but there are multiple issues
included in the report. So I suppose References: is the correct tag
then.
>
>
> BR,
> Jani.
>
>
> > Signed-off-by: Imre Deak
> > ---
> > drivers/gpu/drm/i915/i915_debugfs.c | 24 +++-
> > 1 file changed, 15 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> > b/drivers/gpu/drm/i915/i915_debugfs.c
> > index 2bdce9fea671..8f9045fae3cf 100644
> > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > @@ -1484,9 +1484,12 @@ static int gen6_drpc_info(struct seq_file *m)
> > gen9_powergate_status = I915_READ(GEN9_PWRGT_DOMAIN_STATUS);
> > }
> >
> > - mutex_lock(&dev_priv->pcu_lock);
> > - sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS, &rc6vids);
> > - mutex_unlock(&dev_priv->pcu_lock);
> > + if (INTEL_GEN(dev_priv) <= 7) {
> > + mutex_lock(&dev_priv->pcu_lock);
> > + sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS,
> > + &rc6vids);
> > + mutex_unlock(&dev_priv->pcu_lock);
> > + }
> >
> > seq_printf(m, "RC1e Enabled: %s\n",
> >yesno(rcctl1 & GEN6_RC_CTL_RC1e_ENABLE));
> > @@ -1542,12 +1545,15 @@ static int gen6_drpc_info(struct seq_file *m)
> > print_rc6_res(m, "RC6+ residency since boot:", GEN6_GT_GFX_RC6p);
> > print_rc6_res(m, "RC6++ residency since boot:", GEN6_GT_GFX_RC6pp);
> >
> > - seq_printf(m, "RC6 voltage: %dmV\n",
> > - GEN6_DECODE_RC6_VID(((rc6vids >> 0) & 0xff)));
> > - seq_printf(m, "RC6+ voltage: %dmV\n",
> > - GEN6_DECODE_RC6_VID(((rc6vids >> 8) & 0xff)));
> > - seq_printf(m, "RC6++ voltage: %dmV\n",
> > - GEN6_DECODE_RC6_VID(((rc6vids >> 16) & 0xff)));
> > + if (INTEL_GEN(dev_priv) <= 7) {
> > + seq_printf(m, "RC6 voltage: %dmV\n",
> > + GEN6_DECODE_RC6_VID(((rc6vids >> 0) & 0xff)));
> > + seq_printf(m, "RC6+ voltage: %dmV\n",
> > + GEN6_DECODE_RC6_VID(((rc6vids >> 8) & 0xff)));
> > + seq_printf(m, "RC6++ voltage: %dmV\n",
> > + GEN6_DECODE_RC6_VID(((rc6vids >> 16) & 0xff)));
> > + }
> > +
> > return i915_forcewake_domains(m, NULL);
> > }
>
> --
> Jani Nikula, Intel Open Source Technology Center
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Re: [Intel-gfx] [PATCH] drm/i915: Don't query PCODE RC6VIDS on platforms not supporting it
On Mon, Feb 12, 2018 at 11:19:09AM +, Chris Wilson wrote:
> Quoting Imre Deak (2018-02-08 18:44:41)
> > On Thu, Feb 08, 2018 at 06:33:03PM +, Chris Wilson wrote:
> > > Quoting Imre Deak (2018-02-08 17:41:02)
> > > > On BXT/GLK GEN6_PCODE_READ_RC6VIDS fails with
> > > > MAILBOX_P24C_CC_ILLEGAL_CMD, so don't try to do the query on these
> > > > platforms. Do it only on SNB, IVB and HSW, where we use this command
> > > > anyway for RC6 enabling.
> > > >
> > > > Based on my tests the command also succeeds on all LLC platforms, but
> > > > it's not clear if it's really supported on those (it returns 0 aka 245mv
> > > > for all RC6 states everywhere except on SNB). BSpec lists the command as
> > > > supported on SKL+ (see P24C_PCODE_MAILBOX_INTERFACE) but that's clearly
> > > > incorrect, since on SKL/KBL the same command ID is used for
> > > > SKL_PCODE_LOAD_HDCP_KEYS. Since the command fails on BXT/GLK, the BSpec
> > > > command list is also incorrect for those platforms (see
> > > > P_CR_P24C_PCODE_MAILBOX_INTERFACE_0_2_0_GTTMMADR).
> > > >
> > > > I filed a request to update that info in Bspec, but for now let's
> > > > assume a minimal set of platforms where the command is supported.
> > > >
> > > > Reference: https://bugs.freedesktop.org/show_bug.cgi?id=103337
> > > > Signed-off-by: Imre Deak
> > > > ---
> > > > drivers/gpu/drm/i915/i915_debugfs.c | 24 +++-
> > > > 1 file changed, 15 insertions(+), 9 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> > > > b/drivers/gpu/drm/i915/i915_debugfs.c
> > > > index 2bdce9fea671..8f9045fae3cf 100644
> > > > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > > > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > > > @@ -1484,9 +1484,12 @@ static int gen6_drpc_info(struct seq_file *m)
> > > > gen9_powergate_status =
> > > > I915_READ(GEN9_PWRGT_DOMAIN_STATUS);
> > > > }
> > > >
> > > > - mutex_lock(&dev_priv->pcu_lock);
> > > > - sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS,
> > > > &rc6vids);
> > > > - mutex_unlock(&dev_priv->pcu_lock);
> > > > + if (INTEL_GEN(dev_priv) <= 7) {
> > > > + mutex_lock(&dev_priv->pcu_lock);
> > > > + sandybridge_pcode_read(dev_priv,
> > > > GEN6_PCODE_READ_RC6VIDS,
> > > > + &rc6vids);
> > > > + mutex_unlock(&dev_priv->pcu_lock);
> > > > + }
> > > >
> > > > seq_printf(m, "RC1e Enabled: %s\n",
> > > >yesno(rcctl1 & GEN6_RC_CTL_RC1e_ENABLE));
> > > > @@ -1542,12 +1545,15 @@ static int gen6_drpc_info(struct seq_file *m)
> > > > print_rc6_res(m, "RC6+ residency since boot:",
> > > > GEN6_GT_GFX_RC6p);
> > > > print_rc6_res(m, "RC6++ residency since boot:",
> > > > GEN6_GT_GFX_RC6pp);
> > > >
> > > > - seq_printf(m, "RC6 voltage: %dmV\n",
> > > > - GEN6_DECODE_RC6_VID(((rc6vids >> 0) & 0xff)));
> > > > - seq_printf(m, "RC6+ voltage: %dmV\n",
> > > > - GEN6_DECODE_RC6_VID(((rc6vids >> 8) & 0xff)));
> > > > - seq_printf(m, "RC6++ voltage: %dmV\n",
> > > > - GEN6_DECODE_RC6_VID(((rc6vids >> 16) & 0xff)));
> > > > + if (INTEL_GEN(dev_priv) <= 7) {
> > >
> > > I expect this will confuse gcc-4.4 and it will emit a
> > > maybe-used-uninitialised. I would set rc6vids=0 and then test if
> > > (rc6vids) here.
> >
> > It's inited already to 0, so shouldn't warn. (0 is a valid value
> > otherwise).
>
> (Valid but not validated ;)
True, so we don't know if the platforms returning 0 (with the PCODE
command otherwise succeeding) return an actually correct value. Checking
again it's only SNB where we use the value (so not even IVB/HSW) and
that's the only one returning a non-zero value. I hope someone will
follow-up on my bspec update request and clarify this.
>
> Reviewed-by: Chris Wilson
> -Chris
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Re: [Intel-gfx] [PATCH] drm/i915: Don't query PCODE RC6VIDS on platforms not supporting it
Quoting Imre Deak (2018-02-08 18:44:41)
> On Thu, Feb 08, 2018 at 06:33:03PM +, Chris Wilson wrote:
> > Quoting Imre Deak (2018-02-08 17:41:02)
> > > On BXT/GLK GEN6_PCODE_READ_RC6VIDS fails with
> > > MAILBOX_P24C_CC_ILLEGAL_CMD, so don't try to do the query on these
> > > platforms. Do it only on SNB, IVB and HSW, where we use this command
> > > anyway for RC6 enabling.
> > >
> > > Based on my tests the command also succeeds on all LLC platforms, but
> > > it's not clear if it's really supported on those (it returns 0 aka 245mv
> > > for all RC6 states everywhere except on SNB). BSpec lists the command as
> > > supported on SKL+ (see P24C_PCODE_MAILBOX_INTERFACE) but that's clearly
> > > incorrect, since on SKL/KBL the same command ID is used for
> > > SKL_PCODE_LOAD_HDCP_KEYS. Since the command fails on BXT/GLK, the BSpec
> > > command list is also incorrect for those platforms (see
> > > P_CR_P24C_PCODE_MAILBOX_INTERFACE_0_2_0_GTTMMADR).
> > >
> > > I filed a request to update that info in Bspec, but for now let's
> > > assume a minimal set of platforms where the command is supported.
> > >
> > > Reference: https://bugs.freedesktop.org/show_bug.cgi?id=103337
> > > Signed-off-by: Imre Deak
> > > ---
> > > drivers/gpu/drm/i915/i915_debugfs.c | 24 +++-
> > > 1 file changed, 15 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> > > b/drivers/gpu/drm/i915/i915_debugfs.c
> > > index 2bdce9fea671..8f9045fae3cf 100644
> > > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > > @@ -1484,9 +1484,12 @@ static int gen6_drpc_info(struct seq_file *m)
> > > gen9_powergate_status =
> > > I915_READ(GEN9_PWRGT_DOMAIN_STATUS);
> > > }
> > >
> > > - mutex_lock(&dev_priv->pcu_lock);
> > > - sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS,
> > > &rc6vids);
> > > - mutex_unlock(&dev_priv->pcu_lock);
> > > + if (INTEL_GEN(dev_priv) <= 7) {
> > > + mutex_lock(&dev_priv->pcu_lock);
> > > + sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS,
> > > + &rc6vids);
> > > + mutex_unlock(&dev_priv->pcu_lock);
> > > + }
> > >
> > > seq_printf(m, "RC1e Enabled: %s\n",
> > >yesno(rcctl1 & GEN6_RC_CTL_RC1e_ENABLE));
> > > @@ -1542,12 +1545,15 @@ static int gen6_drpc_info(struct seq_file *m)
> > > print_rc6_res(m, "RC6+ residency since boot:", GEN6_GT_GFX_RC6p);
> > > print_rc6_res(m, "RC6++ residency since boot:",
> > > GEN6_GT_GFX_RC6pp);
> > >
> > > - seq_printf(m, "RC6 voltage: %dmV\n",
> > > - GEN6_DECODE_RC6_VID(((rc6vids >> 0) & 0xff)));
> > > - seq_printf(m, "RC6+ voltage: %dmV\n",
> > > - GEN6_DECODE_RC6_VID(((rc6vids >> 8) & 0xff)));
> > > - seq_printf(m, "RC6++ voltage: %dmV\n",
> > > - GEN6_DECODE_RC6_VID(((rc6vids >> 16) & 0xff)));
> > > + if (INTEL_GEN(dev_priv) <= 7) {
> >
> > I expect this will confuse gcc-4.4 and it will emit a
> > maybe-used-uninitialised. I would set rc6vids=0 and then test if
> > (rc6vids) here.
>
> It's inited already to 0, so shouldn't warn. (0 is a valid value
> otherwise).
(Valid but not validated ;)
Reviewed-by: Chris Wilson
-Chris
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Re: [Intel-gfx] [PATCH] drm/i915: Don't query PCODE RC6VIDS on platforms not supporting it
On Thu, 08 Feb 2018, Imre Deak wrote:
> On BXT/GLK GEN6_PCODE_READ_RC6VIDS fails with
> MAILBOX_P24C_CC_ILLEGAL_CMD, so don't try to do the query on these
> platforms. Do it only on SNB, IVB and HSW, where we use this command
> anyway for RC6 enabling.
>
> Based on my tests the command also succeeds on all LLC platforms, but
> it's not clear if it's really supported on those (it returns 0 aka 245mv
> for all RC6 states everywhere except on SNB). BSpec lists the command as
> supported on SKL+ (see P24C_PCODE_MAILBOX_INTERFACE) but that's clearly
> incorrect, since on SKL/KBL the same command ID is used for
> SKL_PCODE_LOAD_HDCP_KEYS. Since the command fails on BXT/GLK, the BSpec
> command list is also incorrect for those platforms (see
> P_CR_P24C_PCODE_MAILBOX_INTERFACE_0_2_0_GTTMMADR).
>
> I filed a request to update that info in Bspec, but for now let's
> assume a minimal set of platforms where the command is supported.
>
> Reference: https://bugs.freedesktop.org/show_bug.cgi?id=103337
If the patch fixes the bug, please use Bugzilla:.
If the patch is related to the bug, please use References:.
BR,
Jani.
> Signed-off-by: Imre Deak
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 24 +++-
> 1 file changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> b/drivers/gpu/drm/i915/i915_debugfs.c
> index 2bdce9fea671..8f9045fae3cf 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -1484,9 +1484,12 @@ static int gen6_drpc_info(struct seq_file *m)
> gen9_powergate_status = I915_READ(GEN9_PWRGT_DOMAIN_STATUS);
> }
>
> - mutex_lock(&dev_priv->pcu_lock);
> - sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS, &rc6vids);
> - mutex_unlock(&dev_priv->pcu_lock);
> + if (INTEL_GEN(dev_priv) <= 7) {
> + mutex_lock(&dev_priv->pcu_lock);
> + sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS,
> +&rc6vids);
> + mutex_unlock(&dev_priv->pcu_lock);
> + }
>
> seq_printf(m, "RC1e Enabled: %s\n",
> yesno(rcctl1 & GEN6_RC_CTL_RC1e_ENABLE));
> @@ -1542,12 +1545,15 @@ static int gen6_drpc_info(struct seq_file *m)
> print_rc6_res(m, "RC6+ residency since boot:", GEN6_GT_GFX_RC6p);
> print_rc6_res(m, "RC6++ residency since boot:", GEN6_GT_GFX_RC6pp);
>
> - seq_printf(m, "RC6 voltage: %dmV\n",
> -GEN6_DECODE_RC6_VID(((rc6vids >> 0) & 0xff)));
> - seq_printf(m, "RC6+ voltage: %dmV\n",
> -GEN6_DECODE_RC6_VID(((rc6vids >> 8) & 0xff)));
> - seq_printf(m, "RC6++ voltage: %dmV\n",
> -GEN6_DECODE_RC6_VID(((rc6vids >> 16) & 0xff)));
> + if (INTEL_GEN(dev_priv) <= 7) {
> + seq_printf(m, "RC6 voltage: %dmV\n",
> +GEN6_DECODE_RC6_VID(((rc6vids >> 0) & 0xff)));
> + seq_printf(m, "RC6+ voltage: %dmV\n",
> +GEN6_DECODE_RC6_VID(((rc6vids >> 8) & 0xff)));
> + seq_printf(m, "RC6++ voltage: %dmV\n",
> +GEN6_DECODE_RC6_VID(((rc6vids >> 16) & 0xff)));
> + }
> +
> return i915_forcewake_domains(m, NULL);
> }
--
Jani Nikula, Intel Open Source Technology Center
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Re: [Intel-gfx] [PATCH] drm/i915: Don't query PCODE RC6VIDS on platforms not supporting it
On Thu, Feb 08, 2018 at 06:33:03PM +, Chris Wilson wrote:
> Quoting Imre Deak (2018-02-08 17:41:02)
> > On BXT/GLK GEN6_PCODE_READ_RC6VIDS fails with
> > MAILBOX_P24C_CC_ILLEGAL_CMD, so don't try to do the query on these
> > platforms. Do it only on SNB, IVB and HSW, where we use this command
> > anyway for RC6 enabling.
> >
> > Based on my tests the command also succeeds on all LLC platforms, but
> > it's not clear if it's really supported on those (it returns 0 aka 245mv
> > for all RC6 states everywhere except on SNB). BSpec lists the command as
> > supported on SKL+ (see P24C_PCODE_MAILBOX_INTERFACE) but that's clearly
> > incorrect, since on SKL/KBL the same command ID is used for
> > SKL_PCODE_LOAD_HDCP_KEYS. Since the command fails on BXT/GLK, the BSpec
> > command list is also incorrect for those platforms (see
> > P_CR_P24C_PCODE_MAILBOX_INTERFACE_0_2_0_GTTMMADR).
> >
> > I filed a request to update that info in Bspec, but for now let's
> > assume a minimal set of platforms where the command is supported.
> >
> > Reference: https://bugs.freedesktop.org/show_bug.cgi?id=103337
> > Signed-off-by: Imre Deak
> > ---
> > drivers/gpu/drm/i915/i915_debugfs.c | 24 +++-
> > 1 file changed, 15 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> > b/drivers/gpu/drm/i915/i915_debugfs.c
> > index 2bdce9fea671..8f9045fae3cf 100644
> > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > @@ -1484,9 +1484,12 @@ static int gen6_drpc_info(struct seq_file *m)
> > gen9_powergate_status = I915_READ(GEN9_PWRGT_DOMAIN_STATUS);
> > }
> >
> > - mutex_lock(&dev_priv->pcu_lock);
> > - sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS, &rc6vids);
> > - mutex_unlock(&dev_priv->pcu_lock);
> > + if (INTEL_GEN(dev_priv) <= 7) {
> > + mutex_lock(&dev_priv->pcu_lock);
> > + sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS,
> > + &rc6vids);
> > + mutex_unlock(&dev_priv->pcu_lock);
> > + }
> >
> > seq_printf(m, "RC1e Enabled: %s\n",
> >yesno(rcctl1 & GEN6_RC_CTL_RC1e_ENABLE));
> > @@ -1542,12 +1545,15 @@ static int gen6_drpc_info(struct seq_file *m)
> > print_rc6_res(m, "RC6+ residency since boot:", GEN6_GT_GFX_RC6p);
> > print_rc6_res(m, "RC6++ residency since boot:", GEN6_GT_GFX_RC6pp);
> >
> > - seq_printf(m, "RC6 voltage: %dmV\n",
> > - GEN6_DECODE_RC6_VID(((rc6vids >> 0) & 0xff)));
> > - seq_printf(m, "RC6+ voltage: %dmV\n",
> > - GEN6_DECODE_RC6_VID(((rc6vids >> 8) & 0xff)));
> > - seq_printf(m, "RC6++ voltage: %dmV\n",
> > - GEN6_DECODE_RC6_VID(((rc6vids >> 16) & 0xff)));
> > + if (INTEL_GEN(dev_priv) <= 7) {
>
> I expect this will confuse gcc-4.4 and it will emit a
> maybe-used-uninitialised. I would set rc6vids=0 and then test if
> (rc6vids) here.
It's inited already to 0, so shouldn't warn. (0 is a valid value
otherwise).
--Imre
> -Chris
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Re: [Intel-gfx] [PATCH] drm/i915: Don't query PCODE RC6VIDS on platforms not supporting it
Quoting Imre Deak (2018-02-08 17:41:02)
> On BXT/GLK GEN6_PCODE_READ_RC6VIDS fails with
> MAILBOX_P24C_CC_ILLEGAL_CMD, so don't try to do the query on these
> platforms. Do it only on SNB, IVB and HSW, where we use this command
> anyway for RC6 enabling.
>
> Based on my tests the command also succeeds on all LLC platforms, but
> it's not clear if it's really supported on those (it returns 0 aka 245mv
> for all RC6 states everywhere except on SNB). BSpec lists the command as
> supported on SKL+ (see P24C_PCODE_MAILBOX_INTERFACE) but that's clearly
> incorrect, since on SKL/KBL the same command ID is used for
> SKL_PCODE_LOAD_HDCP_KEYS. Since the command fails on BXT/GLK, the BSpec
> command list is also incorrect for those platforms (see
> P_CR_P24C_PCODE_MAILBOX_INTERFACE_0_2_0_GTTMMADR).
>
> I filed a request to update that info in Bspec, but for now let's
> assume a minimal set of platforms where the command is supported.
>
> Reference: https://bugs.freedesktop.org/show_bug.cgi?id=103337
> Signed-off-by: Imre Deak
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 24 +++-
> 1 file changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> b/drivers/gpu/drm/i915/i915_debugfs.c
> index 2bdce9fea671..8f9045fae3cf 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -1484,9 +1484,12 @@ static int gen6_drpc_info(struct seq_file *m)
> gen9_powergate_status = I915_READ(GEN9_PWRGT_DOMAIN_STATUS);
> }
>
> - mutex_lock(&dev_priv->pcu_lock);
> - sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS, &rc6vids);
> - mutex_unlock(&dev_priv->pcu_lock);
> + if (INTEL_GEN(dev_priv) <= 7) {
> + mutex_lock(&dev_priv->pcu_lock);
> + sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS,
> + &rc6vids);
> + mutex_unlock(&dev_priv->pcu_lock);
> + }
>
> seq_printf(m, "RC1e Enabled: %s\n",
>yesno(rcctl1 & GEN6_RC_CTL_RC1e_ENABLE));
> @@ -1542,12 +1545,15 @@ static int gen6_drpc_info(struct seq_file *m)
> print_rc6_res(m, "RC6+ residency since boot:", GEN6_GT_GFX_RC6p);
> print_rc6_res(m, "RC6++ residency since boot:", GEN6_GT_GFX_RC6pp);
>
> - seq_printf(m, "RC6 voltage: %dmV\n",
> - GEN6_DECODE_RC6_VID(((rc6vids >> 0) & 0xff)));
> - seq_printf(m, "RC6+ voltage: %dmV\n",
> - GEN6_DECODE_RC6_VID(((rc6vids >> 8) & 0xff)));
> - seq_printf(m, "RC6++ voltage: %dmV\n",
> - GEN6_DECODE_RC6_VID(((rc6vids >> 16) & 0xff)));
> + if (INTEL_GEN(dev_priv) <= 7) {
I expect this will confuse gcc-4.4 and it will emit a
maybe-used-uninitialised. I would set rc6vids=0 and then test if
(rc6vids) here.
-Chris
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