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author | David S. Miller <davem@davemloft.net> | 2015-09-26 23:08:27 (GMT) |
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committer | David S. Miller <davem@davemloft.net> | 2015-09-26 23:08:27 (GMT) |
commit | 4963ed48f2c20196d51a447ee87dc2815584fee4 (patch) | |
tree | a1902f466dafa00453889a4f1e66b00249ce0529 /drivers/gpu/drm/i915/i915_irq.c | |
parent | 4d54d86546f62c7c4a0fe3b36a64c5e3b98ce1a9 (diff) | |
parent | 518a7cb6980cd640c7f979d29021ad870f60d7d7 (diff) | |
download | linux-4963ed48f2c20196d51a447ee87dc2815584fee4.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
net/ipv4/arp.c
The net/ipv4/arp.c conflict was one commit adding a new
local variable while another commit was deleting one.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_irq.c')
-rw-r--r-- | drivers/gpu/drm/i915/i915_irq.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 5a244ab..39d73db 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -640,6 +640,32 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc) position = __raw_i915_read32(dev_priv, PIPEDSL(pipe)) & DSL_LINEMASK_GEN3; /* + * On HSW, the DSL reg (0x70000) appears to return 0 if we + * read it just before the start of vblank. So try it again + * so we don't accidentally end up spanning a vblank frame + * increment, causing the pipe_update_end() code to squak at us. + * + * The nature of this problem means we can't simply check the ISR + * bit and return the vblank start value; nor can we use the scanline + * debug register in the transcoder as it appears to have the same + * problem. We may need to extend this to include other platforms, + * but so far testing only shows the problem on HSW. + */ + if (IS_HASWELL(dev) && !position) { + int i, temp; + + for (i = 0; i < 100; i++) { + udelay(1); + temp = __raw_i915_read32(dev_priv, PIPEDSL(pipe)) & + DSL_LINEMASK_GEN3; + if (temp != position) { + position = temp; + break; + } + } + } + + /* * See update_scanline_offset() for the details on the * scanline_offset adjustment. */ |