diff mbox series

[v6,02/12] drm/i915/mtl: Synchronize i915/BIOS on C6 enabling

Message ID 20230316010101.2590309-3-umesh.nerlige.ramappa@intel.com (mailing list archive)
State New, archived
Headers show
Series Add OAM support for MTL | expand

Commit Message

Umesh Nerlige Ramappa March 16, 2023, 1 a.m. UTC 
From: Vinay Belgaumkar <vinay.belgaumkar@intel.com>

If BIOS enables/disables C6, i915 should do the same. Also, retain
this value across driver reloads. This is needed only for MTL as
of now due to an existing bug in OA which needs C6 disabled for
it to function. BIOS behavior is also different across platforms
in terms of how C6 is enabled.

Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_rc6.c       | 26 ++++++++++++++++++++---
 drivers/gpu/drm/i915/gt/intel_rc6.h       |  2 ++
 drivers/gpu/drm/i915/gt/intel_rc6_types.h |  2 ++
 3 files changed, 27 insertions(+), 3 deletions(-)

Comments

Dixit, Ashutosh March 17, 2023, 3:43 a.m. UTC | #1 
On Wed, 15 Mar 2023 18:00:51 -0700, Umesh Nerlige Ramappa wrote:
>
> From: Vinay Belgaumkar <vinay.belgaumkar@intel.com>

Hi Vinay,

> If BIOS enables/disables C6, i915 should do the same.

So MTL bios has a control for enabling/disabling C6? Both RC6 and MC6
individually or collectively?

What happens if bios has disabled RC6 and i915 enables it: just that it
will bust OA?

The patch itself LGTM if the above is true, I can R-b it after I hear about
the above.

Thanks.
--
Ashutosh

> Also, retain this value across driver reloads. This is needed only for
> MTL as of now due to an existing bug in OA which needs C6 disabled for it
> to function. BIOS behavior is also different across platforms in terms of
> how C6 is enabled.
>
> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Dixit, Ashutosh March 17, 2023, 5:24 a.m. UTC | #2 
On Thu, 16 Mar 2023 20:43:39 -0700, Dixit, Ashutosh wrote:
>
> On Wed, 15 Mar 2023 18:00:51 -0700, Umesh Nerlige Ramappa wrote:
> >
> > From: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
>
> Hi Vinay,
>
> > If BIOS enables/disables C6, i915 should do the same.
>
> So MTL bios has a control for enabling/disabling C6? Both RC6 and MC6
> individually or collectively?
>
> What happens if bios has disabled RC6 and i915 enables it: just that it
> will bust OA?
>
> The patch itself LGTM if the above is true, I can R-b it after I hear about
> the above.
>
> Thanks.
> --
> Ashutosh
>
> > Also, retain this value across driver reloads. This is needed only for
> > MTL as of now due to an existing bug in OA which needs C6 disabled for it

Let's say "C6 disabled in BIOS for it to function".

> > to function. BIOS behavior is also different across platforms in terms of
> > how C6 is enabled.
> >
> > Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>

Otherwise as promised above:

Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Vinay Belgaumkar March 17, 2023, 6:26 p.m. UTC | #3 
On 3/16/2023 8:43 PM, Dixit, Ashutosh wrote:
> On Wed, 15 Mar 2023 18:00:51 -0700, Umesh Nerlige Ramappa wrote:
>> From: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> Hi Vinay,
>
>> If BIOS enables/disables C6, i915 should do the same.
> So MTL bios has a control for enabling/disabling C6? Both RC6 and MC6
> individually or collectively?
Yes, we can toggle both independently in BIOS.
>
> What happens if bios has disabled RC6 and i915 enables it: just that it
> will bust OA?

Yes, since OA init will rely on this information.

Thanks,

Vinay.

>
> The patch itself LGTM if the above is true, I can R-b it after I hear about
> the above.
>
> Thanks.
> --
> Ashutosh
>
>> Also, retain this value across driver reloads. This is needed only for
>> MTL as of now due to an existing bug in OA which needs C6 disabled for it
>> to function. BIOS behavior is also different across platforms in terms of
>> how C6 is enabled.
>>
>> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gt/intel_rc6.c b/drivers/gpu/drm/i915/gt/intel_rc6.c
index f4150f61f39c..f760586f9f46 100644
--- a/drivers/gpu/drm/i915/gt/intel_rc6.c
+++ b/drivers/gpu/drm/i915/gt/intel_rc6.c
@@ -420,6 +420,21 @@  static void vlv_rc6_enable(struct intel_rc6 *rc6)
 	    GEN7_RC_CTL_TO_MODE | VLV_RC_CTL_CTX_RST_PARALLEL;
 }
 
+bool intel_check_bios_c6_setup(struct intel_rc6 *rc6)
+{
+	if (!rc6->bios_state_captured) {
+		struct intel_uncore *uncore = rc6_to_uncore(rc6);
+		intel_wakeref_t wakeref;
+
+		with_intel_runtime_pm(uncore->rpm, wakeref)
+			rc6->bios_rc_state = intel_uncore_read(uncore, GEN6_RC_STATE);
+
+		rc6->bios_state_captured = true;
+	}
+
+	return rc6->bios_rc_state & RC_SW_TARGET_STATE_MASK;
+}
+
 static bool bxt_check_bios_rc6_setup(struct intel_rc6 *rc6)
 {
 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
@@ -503,10 +518,10 @@  static bool rc6_supported(struct intel_rc6 *rc6)
 		return false;
 	}
 
-	if (IS_MTL_MEDIA_STEP(gt->i915, STEP_A0, STEP_B0) &&
-	    gt->type == GT_MEDIA) {
+	if (IS_METEORLAKE(gt->i915) &&
+	    !intel_check_bios_c6_setup(rc6)) {
 		drm_notice(&i915->drm,
-			   "Media RC6 disabled on A step\n");
+			   "C6 disabled by BIOS\n");
 		return false;
 	}
 
@@ -707,9 +722,14 @@  void intel_rc6_disable(struct intel_rc6 *rc6)
 void intel_rc6_fini(struct intel_rc6 *rc6)
 {
 	struct drm_i915_gem_object *pctx;
+	struct intel_uncore *uncore = rc6_to_uncore(rc6);
 
 	intel_rc6_disable(rc6);
 
+	/* We want the BIOS C6 state preserved across loads for MTL */
+	if (IS_METEORLAKE(rc6_to_i915(rc6)) && rc6->bios_state_captured)
+		set(uncore, GEN6_RC_STATE, rc6->bios_rc_state);
+
 	pctx = fetch_and_zero(&rc6->pctx);
 	if (pctx)
 		i915_gem_object_put(pctx);
diff --git a/drivers/gpu/drm/i915/gt/intel_rc6.h b/drivers/gpu/drm/i915/gt/intel_rc6.h
index 456fa668a276..e137c2c397c2 100644
--- a/drivers/gpu/drm/i915/gt/intel_rc6.h
+++ b/drivers/gpu/drm/i915/gt/intel_rc6.h
@@ -27,4 +27,6 @@  u64 intel_rc6_residency_us(struct intel_rc6 *rc6, enum intel_rc6_res_type id);
 void intel_rc6_print_residency(struct seq_file *m, const char *title,
 			       enum intel_rc6_res_type id);
 
+bool intel_check_bios_c6_setup(struct intel_rc6 *rc6);
+
 #endif /* INTEL_RC6_H */
diff --git a/drivers/gpu/drm/i915/gt/intel_rc6_types.h b/drivers/gpu/drm/i915/gt/intel_rc6_types.h
index fa23c4dce00b..cd4587098162 100644
--- a/drivers/gpu/drm/i915/gt/intel_rc6_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_rc6_types.h
@@ -29,6 +29,7 @@  struct intel_rc6 {
 	u64 cur_residency[INTEL_RC6_RES_MAX];
 
 	u32 ctl_enable;
+	u32 bios_rc_state;
 
 	struct drm_i915_gem_object *pctx;
 
@@ -36,6 +37,7 @@  struct intel_rc6 {
 	bool enabled : 1;
 	bool manual : 1;
 	bool wakeref : 1;
+	bool bios_state_captured : 1;
 };
 
 #endif /* INTEL_RC6_TYPES_H */