From: Tim Gardner Date: Fri, 9 Jul 2010 20:48:50 +0000 (-0600) Subject: agp/intel: Use the correct mask to detect i830 aperture size. X-Git-Tag: v2.6.35~33^2~4 X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=e7b96f28c58ca09f15f6c2e8ccbb889a30fab4f7 agp/intel: Use the correct mask to detect i830 aperture size. BugLink: https://bugs.launchpad.net/bugs/597075 commit f1befe71fa7a79ab733011b045639d8d809924ad introduced a regression when detecting aperture size of some i915 adapters, e.g., those on the Intel Q35 chipset. The original report: https://bugzilla.kernel.org/show_bug.cgi?id=15733 The regression report: https://bugzilla.kernel.org/show_bug.cgi?id=16294 According to the specification found at http://intellinuxgraphics.org/VOL_1_graphics_core.pdf, the PCI config space register I830_GMCH_CTRL is a mirror of GMCH Graphics Control. The correct macro for isolating the aperture size bits is therefore I830_GMCH_GMS_MASK along with the attendant changes to the case statement. Signed-off-by: Tim Gardner Tested-by: Kees Cook Cc: Chris Wilson Cc: Eric Anholt Cc: Jesse Barnes Signed-off-by: Eric Anholt --- diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c index 9344216..a754715 100644 --- a/drivers/char/agp/intel-gtt.c +++ b/drivers/char/agp/intel-gtt.c @@ -1216,17 +1216,20 @@ static int intel_i915_get_gtt_size(void) /* G33's GTT size defined in gmch_ctrl */ pci_read_config_word(agp_bridge->dev, I830_GMCH_CTRL, &gmch_ctrl); - switch (gmch_ctrl & G33_PGETBL_SIZE_MASK) { - case G33_PGETBL_SIZE_1M: + switch (gmch_ctrl & I830_GMCH_GMS_MASK) { + case I830_GMCH_GMS_STOLEN_512: + size = 512; + break; + case I830_GMCH_GMS_STOLEN_1024: size = 1024; break; - case G33_PGETBL_SIZE_2M: - size = 2048; + case I830_GMCH_GMS_STOLEN_8192: + size = 8*1024; break; default: dev_info(&agp_bridge->dev->dev, "unknown page table size 0x%x, assuming 512KB\n", - (gmch_ctrl & G33_PGETBL_SIZE_MASK)); + (gmch_ctrl & I830_GMCH_GMS_MASK)); size = 512; } } else {