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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2017-01-24 11:00:06 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2017-01-24 15:56:18 +0000 |
| commit | a37951ac9f9642819e400814f6f30689db233c24 (patch) | |
| tree | 26fc89da50390b97f47b970d99a4079eea95e463 /drivers/gpu/drm/i915/intel_lrc.c | |
| parent | f747026c2b350fdb3c2d6fad51b7ebed4851183e (diff) | |
| download | op-kernel-dev-a37951ac9f9642819e400814f6f30689db233c24.zip op-kernel-dev-a37951ac9f9642819e400814f6f30689db233c24.tar.gz | |
drm/i915: Skip the execlists CSB scan and rewrite if the ring is untouched
If the CSB head/tail pointers are unchanged, we can skip the update of
the CSB register afterwards.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170124110009.28947-5-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/intel_lrc.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_lrc.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index f729568..99ab2d7 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -574,9 +574,12 @@ static void intel_lrc_irq_handler(unsigned long data) csb = readl(csb_mmio); head = GEN8_CSB_READ_PTR(csb); tail = GEN8_CSB_WRITE_PTR(csb); + if (head == tail) + break; + if (tail < head) tail += GEN8_CSB_ENTRIES; - while (head < tail) { + do { unsigned int idx = ++head % GEN8_CSB_ENTRIES; unsigned int status = readl(buf + 2 * idx); @@ -601,7 +604,7 @@ static void intel_lrc_irq_handler(unsigned long data) GEM_BUG_ON(port[0].count == 0 && !(status & GEN8_CTX_STATUS_ACTIVE_IDLE)); - } + } while (head < tail); writel(_MASKED_FIELD(GEN8_CSB_READ_PTR_MASK, GEN8_CSB_WRITE_PTR(csb) << 8), |
