| Message ID | 1485324296-14995-1-git-send-email-weinan.z.li@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jan 25, 2017 at 02:04:55PM +0800, Weinan Li wrote:
> No need to do posting read when vgpu actived.
No. This is bloat for no gain. Almost all of those posting
reads are superfluous anyway.
-Chris
I am not sure if native driver still need POSTING_READ action. But for guest we can remove it directly. Search the code, there are still upon 270 hints use POSTING_READ. For guest OS, one frequent POSTING_READ_FW action is in irq handler, it will impact the performance if there is heavy interrupts(like media reference usage.) Thanks. Best Regards. Weinan, LI > -----Original Message----- > From: Chris Wilson [mailto:chris@chris-wilson.co.uk] > Sent: Wednesday, January 25, 2017 3:13 PM > To: Li, Weinan Z <weinan.z.li@intel.com> > Cc: intel-gfx@lists.freedesktop.org; intel-gvt-dev@lists.freedesktop.org > Subject: Re: [Intel-gfx] [PATCH 1/2] drm/i915: ignore posting read when > using vgpu > > On Wed, Jan 25, 2017 at 02:04:55PM +0800, Weinan Li wrote: > > No need to do posting read when vgpu actived. > > No. This is bloat for no gain. Almost all of those posting reads are superfluous > anyway. > -Chris > > -- > Chris Wilson, Intel Open Source Technology Centre
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 52d01be..8c9d81b 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3830,8 +3830,11 @@ void vlv_set_phy_signal_level(struct intel_encoder *encoder, } while (upper != old_upper && loop++ < 2); \ (u64)upper << 32 | lower; }) -#define POSTING_READ(reg) (void)I915_READ_NOTRACE(reg) -#define POSTING_READ16(reg) (void)I915_READ16_NOTRACE(reg) +#define POSTING_READ(reg) ( \ + intel_vgpu_active(dev_priv) ? (void)0 : (void)I915_READ_NOTRACE(reg)) + +#define POSTING_READ16(reg) ( \ + intel_vgpu_active(dev_priv) ? (void)0 : (void)I915_READ16_NOTRACE(reg)) #define __raw_read(x, s) \ static inline uint##x##_t __raw_i915_read##x(struct drm_i915_private *dev_priv, \ @@ -3888,7 +3891,8 @@ void vlv_set_phy_signal_level(struct intel_encoder *encoder, #define I915_READ_FW(reg__) __raw_i915_read32(dev_priv, (reg__)) #define I915_WRITE_FW(reg__, val__) __raw_i915_write32(dev_priv, (reg__), (val__)) #define I915_WRITE64_FW(reg__, val__) __raw_i915_write64(dev_priv, (reg__), (val__)) -#define POSTING_READ_FW(reg__) (void)I915_READ_FW(reg__) +#define POSTING_READ_FW(reg__) ( \ + intel_vgpu_active(dev_priv) ? (void)0 : (void)I915_READ_FW(reg__)) /* "Broadcast RGB" property */ #define INTEL_BROADCAST_RGB_AUTO 0
No need to do posting read when vgpu actived. Signed-off-by: Weinan Li <weinan.z.li@intel.com> --- drivers/gpu/drm/i915/i915_drv.h | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)