From 36c0cc616e518bfc2b685bed7fb3243d1242eca4 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Tue, 9 Jul 2013 14:44:26 +0200 Subject: [PATCH] drm/i915: clean up media reset on gm45 Originally I've thought that this fixes up the reset issues on my gm45, but that was just a red herring due to b0rked testing. Still I much prefer writing the right values (all other fields are reserved) instead of potentially dragging gunk around. Hence also clear the register to 0 after a reset. Note that Cspec is a bit confused and doesn't explicitly say that all the other bits in this register are "reserved, mbz" like usually. Instead they're marked as "r/o, default value = 0" which semantically amounts to the same thing. v2: Stop claiming this fixes anything and return 0 if successful instead of stack garbage. v3: Pimp the commit message to explain exactly why I think the docs allow us to ditch the rmw cycle, spurred by a discussion with Chris. Cc: Chris Wilson Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_drv.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 33cb973..ed9262c 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -798,28 +798,29 @@ static int i965_reset_complete(struct drm_device *dev) static int i965_do_reset(struct drm_device *dev) { int ret; - u8 gdrst; /* * Set the domains we want to reset (GRDOM/bits 2 and 3) as * well as the reset bit (GR/bit 0). Setting the GR bit * triggers the reset; when done, the hardware will clear it. */ - pci_read_config_byte(dev->pdev, I965_GDRST, &gdrst); pci_write_config_byte(dev->pdev, I965_GDRST, - gdrst | GRDOM_RENDER | - GRDOM_RESET_ENABLE); + GRDOM_RENDER | GRDOM_RESET_ENABLE); ret = wait_for(i965_reset_complete(dev), 500); if (ret) return ret; /* We can't reset render&media without also resetting display ... */ - pci_read_config_byte(dev->pdev, I965_GDRST, &gdrst); pci_write_config_byte(dev->pdev, I965_GDRST, - gdrst | GRDOM_MEDIA | - GRDOM_RESET_ENABLE); + GRDOM_MEDIA | GRDOM_RESET_ENABLE); - return wait_for(i965_reset_complete(dev), 500); + ret = wait_for(i965_reset_complete(dev), 500); + if (ret) + return ret; + + pci_write_config_byte(dev->pdev, I965_GDRST, 0); + + return 0; } static int ironlake_do_reset(struct drm_device *dev) -- 2.7.4