From 3617dc9675f0184b7bb210cfa34f3cac928d8055 Mon Sep 17 00:00:00 2001 From: Akash Goel Date: Mon, 13 Jan 2014 16:25:21 +0530 Subject: [PATCH] drm/i915: Resolving the memory region conflict for Stolen area There is a conflict seen when requesting the kernel to reserve the physical space used for the stolen area. This is because some BIOS are wrapping the stolen area in the root PCI bus, but have an off-by-one error. As a workaround we retry the reservation with an offset of 1 instead of 0. v2: updated commit message & the comment in source file (Daniel) Signed-off-by: Akash Goel Reviewed-by: Jesse Barnes Tested-by: Arjan van de Ven Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/i915_gem_stolen.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index 1a24e84f2315..d58b4e287e32 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -82,9 +82,22 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev) r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size, "Graphics Stolen Memory"); if (r == NULL) { - DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n", - base, base + (uint32_t)dev_priv->gtt.stolen_size); - base = 0; + /* + * One more attempt but this time requesting region from + * base + 1, as we have seen that this resolves the region + * conflict with the PCI Bus. + * This is a BIOS w/a: Some BIOS wrap stolen in the root + * PCI bus, but have an off-by-one error. Hence retry the + * reservation starting from 1 instead of 0. + */ + r = devm_request_mem_region(dev->dev, base + 1, + dev_priv->gtt.stolen_size - 1, + "Graphics Stolen Memory"); + if (r == NULL) { + DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n", + base, base + (uint32_t)dev_priv->gtt.stolen_size); + base = 0; + } } return base; -- 2.34.1