| Message ID | 1440332571-20761-2-git-send-email-sagar.a.kamble@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Aug 23, 2015 at 05:52:47PM +0530, Sagar Arun Kamble wrote: > On BXT, We Observe timeout for forcewake request completion with 2ms polling period as given here: > [drm:fw_domains_get] ERROR render: timed out waiting for forcewake ack request. > Polling for 50ms is recommended to avoid these timeouts. > > Change-Id: Ie715b0069a3049606e9602bc5e97a6511890864d > Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> Probably needs cc: stable plus a pile of bugzilla links all over ... -Daniel > --- > drivers/gpu/drm/i915/intel_uncore.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c > index 9d3c2e4..2df03b1 100644 > --- a/drivers/gpu/drm/i915/intel_uncore.c > +++ b/drivers/gpu/drm/i915/intel_uncore.c > @@ -27,7 +27,7 @@ > > #include <linux/pm_runtime.h> > > -#define FORCEWAKE_ACK_TIMEOUT_MS 2 > +#define FORCEWAKE_ACK_TIMEOUT_MS 50 > > #define __raw_i915_read8(dev_priv__, reg__) readb((dev_priv__)->regs + (reg__)) > #define __raw_i915_write8(dev_priv__, reg__, val__) writeb(val__, (dev_priv__)->regs + (reg__)) > -- > 1.9.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Looks fine to me. Reviewed by: Alex Dai <yu.dai@intel.com>. On 08/23/2015 05:22 AM, Sagar Arun Kamble wrote: > On BXT, We Observe timeout for forcewake request completion with 2ms polling period as given here: > [drm:fw_domains_get] ERROR render: timed out waiting for forcewake ack request. > Polling for 50ms is recommended to avoid these timeouts. > > Change-Id: Ie715b0069a3049606e9602bc5e97a6511890864d > Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> > --- > drivers/gpu/drm/i915/intel_uncore.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c > index 9d3c2e4..2df03b1 100644 > --- a/drivers/gpu/drm/i915/intel_uncore.c > +++ b/drivers/gpu/drm/i915/intel_uncore.c > @@ -27,7 +27,7 @@ > > #include <linux/pm_runtime.h> > > -#define FORCEWAKE_ACK_TIMEOUT_MS 2 > +#define FORCEWAKE_ACK_TIMEOUT_MS 50 > > #define __raw_i915_read8(dev_priv__, reg__) readb((dev_priv__)->regs + (reg__)) > #define __raw_i915_write8(dev_priv__, reg__, val__) writeb(val__, (dev_priv__)->regs + (reg__))
On 08/26/2015 10:26 AM, Daniel Vetter wrote: > On Sun, Aug 23, 2015 at 05:52:47PM +0530, Sagar Arun Kamble wrote: >> On BXT, We Observe timeout for forcewake request completion with 2ms polling period as given here: >> [drm:fw_domains_get] ERROR render: timed out waiting for forcewake ack request. >> Polling for 50ms is recommended to avoid these timeouts. >> >> Change-Id: Ie715b0069a3049606e9602bc5e97a6511890864d >> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> > > Probably needs cc: stable plus a pile of bugzilla links all over ... If the required wait is typically that long, shouldn't we be worried about busy polling? Regards, Tvrtko
On Tue, Sep 22, 2015 at 10:06:47AM +0100, Tvrtko Ursulin wrote: > > On 08/26/2015 10:26 AM, Daniel Vetter wrote: > >On Sun, Aug 23, 2015 at 05:52:47PM +0530, Sagar Arun Kamble wrote: > >>On BXT, We Observe timeout for forcewake request completion with 2ms polling period as given here: > >>[drm:fw_domains_get] ERROR render: timed out waiting for forcewake ack request. > >>Polling for 50ms is recommended to avoid these timeouts. > >> > >>Change-Id: Ie715b0069a3049606e9602bc5e97a6511890864d > >>Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> > > > >Probably needs cc: stable plus a pile of bugzilla links all over ... > > If the required wait is typically that long, shouldn't we be worried > about busy polling? With an exponential backoff (i.e. busyspin for the first ~jiffie/1ms) then usleep_range 1, 2, 4, 8,..? And also keeping the fw wakelock for longer than a jiffie to optimistically avoid these multi-jiffie stalls. Whilst grumbling. -Chris
On 09/22/2015 10:15 AM, Chris Wilson wrote: > On Tue, Sep 22, 2015 at 10:06:47AM +0100, Tvrtko Ursulin wrote: >> >> On 08/26/2015 10:26 AM, Daniel Vetter wrote: >>> On Sun, Aug 23, 2015 at 05:52:47PM +0530, Sagar Arun Kamble wrote: >>>> On BXT, We Observe timeout for forcewake request completion with 2ms polling period as given here: >>>> [drm:fw_domains_get] ERROR render: timed out waiting for forcewake ack request. >>>> Polling for 50ms is recommended to avoid these timeouts. >>>> >>>> Change-Id: Ie715b0069a3049606e9602bc5e97a6511890864d >>>> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> >>> >>> Probably needs cc: stable plus a pile of bugzilla links all over ... >> >> If the required wait is typically that long, shouldn't we be worried >> about busy polling? > > With an exponential backoff (i.e. busyspin for the first ~jiffie/1ms) > then usleep_range 1, 2, 4, 8,..? > > And also keeping the fw wakelock for longer than a jiffie to > optimistically avoid these multi-jiffie stalls. Whilst grumbling. For the atomic case holding it longer is the only option. But key is how typical or atypical these long waits are. Measuring that together with power use sounds critical. Spread of required waits would also give the answer to what the best sleeping strategy for the non-atomic case is. Regards, Tvrtko
On Mon, Sep 21, 2015 at 09:43:06AM -0700, Yu Dai wrote: > Looks fine to me. > Reviewed by: Alex Dai <yu.dai@intel.com>. > > On 08/23/2015 05:22 AM, Sagar Arun Kamble wrote: > >On BXT, We Observe timeout for forcewake request completion with 2ms polling period as given here: > >[drm:fw_domains_get] ERROR render: timed out waiting for forcewake ack request. > >Polling for 50ms is recommended to avoid these timeouts. > > > >Change-Id: Ie715b0069a3049606e9602bc5e97a6511890864d > >Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> Queued for -next, thanks for the patch. -Daniel > >--- > > drivers/gpu/drm/i915/intel_uncore.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > >diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c > >index 9d3c2e4..2df03b1 100644 > >--- a/drivers/gpu/drm/i915/intel_uncore.c > >+++ b/drivers/gpu/drm/i915/intel_uncore.c > >@@ -27,7 +27,7 @@ > > #include <linux/pm_runtime.h> > >-#define FORCEWAKE_ACK_TIMEOUT_MS 2 > >+#define FORCEWAKE_ACK_TIMEOUT_MS 50 > > #define __raw_i915_read8(dev_priv__, reg__) readb((dev_priv__)->regs + (reg__)) > > #define __raw_i915_write8(dev_priv__, reg__, val__) writeb(val__, (dev_priv__)->regs + (reg__)) > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index 9d3c2e4..2df03b1 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -27,7 +27,7 @@ #include <linux/pm_runtime.h> -#define FORCEWAKE_ACK_TIMEOUT_MS 2 +#define FORCEWAKE_ACK_TIMEOUT_MS 50 #define __raw_i915_read8(dev_priv__, reg__) readb((dev_priv__)->regs + (reg__)) #define __raw_i915_write8(dev_priv__, reg__, val__) writeb(val__, (dev_priv__)->regs + (reg__))
On BXT, We Observe timeout for forcewake request completion with 2ms polling period as given here: [drm:fw_domains_get] ERROR render: timed out waiting for forcewake ack request. Polling for 50ms is recommended to avoid these timeouts. Change-Id: Ie715b0069a3049606e9602bc5e97a6511890864d Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com> --- drivers/gpu/drm/i915/intel_uncore.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)