The patch titled intel-agp: avoid oops for G33 on 1MB stolen case has been added to the -mm tree. Its filename is intel-agp-avoid-oops-for-g33-on-1mb-stolen-case.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: intel-agp: avoid oops for G33 on 1MB stolen case From: Brandon Philips <bphilips@xxxxxxx> This is similar to f443675affe3f16dd428e46f0f7fd3f4d703eeab which was reverted because it broke older X.org driver. This patch only fixes the 1MB stolen case since it causes an oops. Xorg will not work without the accompanying patch[1] but avoiding an oops and making it possible to work with patched xorg driver is reasonable. [1] http://ifup.org/~philips/review/xf86-video-intel-G33-1mb.patch Explanation of the oops: > static void intel_i830_init_gtt_entries(void) ... > } else if (IS_G33) { > /* G33's GTT size defined in gmch_ctrl */ > switch (gmch_ctrl & G33_PGETBL_SIZE_MASK) { > case G33_PGETBL_SIZE_1M: > size = 1024; > break; ... > size += 4; size = 1028 Then since we have the BIOS setting 1MB for the device in the GMCH control we get to here: > } else { > switch (gmch_ctrl & I855_GMCH_GMS_MASK) { > case I855_GMCH_GMS_STOLEN_1M: > gtt_entries = MB(1) - KB(size); > break; MB(1) = 1 * 1024 * 1024 KB(1028) = 1028 * 1024 MB(1) - KB(1028) = -4096 > gtt_entries /= KB(4); > intel_private.gtt_entries = gtt_entries; We end up with -1 in gtt_entries. This leads to intel_i915_configure reading/writing to areas outside of mapped memory and the oops. Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=391261 Signed-off-by: Brandon Philips <bphilips@xxxxxxx> Cc: Dave Airlie <airlied@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/char/agp/intel-agp.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff -puN drivers/char/agp/intel-agp.c~intel-agp-avoid-oops-for-g33-on-1mb-stolen-case drivers/char/agp/intel-agp.c --- a/drivers/char/agp/intel-agp.c~intel-agp-avoid-oops-for-g33-on-1mb-stolen-case +++ a/drivers/char/agp/intel-agp.c @@ -561,6 +561,14 @@ static void intel_i830_init_gtt_entries( } else { switch (gmch_ctrl & I855_GMCH_GMS_MASK) { case I855_GMCH_GMS_STOLEN_1M: + if (IS_G33) { + size = 0; + printk(KERN_WARNING PFX + "Warning: G33 chipset with 1MB" + " allocated. Older X.org Intel drivers" + " will not work.\n"); + WARN_ON(1); + } gtt_entries = MB(1) - KB(size); break; case I855_GMCH_GMS_STOLEN_4M: _ Patches currently in -mm which might be from bphilips@xxxxxxx are origin.patch intel-agp-avoid-oops-for-g33-on-1mb-stolen-case.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html