projects / people / pmueller / ipfire-2.x.git / blame
| Commit | Line | Data |
|---|---|---|
| 2cb7cef9 BS |
1 | From: Brandon Philips <bphilips@suse.de> |
| 2 | Subject: Avoid oops on G33 in 1MB stolen Mem case | |
| 3 | References: bnc#391261 | |
| 4 | Patch-Mainline: soon (see bug for ref) | |
| 5 | ||
| 6 | This is similar to f443675affe3f16dd428e46f0f7fd3f4d703eeab which was | |
| 7 | reverted because it broke with older XOrg driver. This patch only fixes | |
| 8 | the 1MB stolen case since it causes an oops due to a calculation | |
| 9 | problem. | |
| 10 | ||
| 11 | This will not work with older X drivers without the accompanying patch | |
| 12 | but I think avoiding an oops and making it possible to work with an | |
| 13 | up-to-date xorg driver is reasonable. | |
| 14 | ||
| 15 | Explanation of the oops: | |
| 16 | ||
| 17 | > static void intel_i830_init_gtt_entries(void) | |
| 18 | ... | |
| 19 | > } else if (IS_G33) { | |
| 20 | > /* G33's GTT size defined in gmch_ctrl */ | |
| 21 | > switch (gmch_ctrl & G33_PGETBL_SIZE_MASK) { | |
| 22 | > case G33_PGETBL_SIZE_1M: | |
| 23 | > size = 1024; | |
| 24 | > break; | |
| 25 | ... | |
| 26 | > size += 4; | |
| 27 | ||
| 28 | size = 1028 | |
| 29 | ||
| 30 | Then since we have the BIOS setting 1MB for the device in the GMCH | |
| 31 | control we get to here: | |
| 32 | ||
| 33 | > } else { | |
| 34 | > switch (gmch_ctrl & I855_GMCH_GMS_MASK) { | |
| 35 | > case I855_GMCH_GMS_STOLEN_1M: | |
| 36 | > gtt_entries = MB(1) - KB(size); | |
| 37 | > break; | |
| 38 | ||
| 39 | MB(1) = 1 * 1024 * 1024 | |
| 40 | KB(1028) = 1028 * 1024 | |
| 41 | ||
| 42 | MB(1) - KB(1028) = -4096 | |
| 43 | ||
| 44 | > gtt_entries /= KB(4); | |
| 45 | > intel_private.gtt_entries = gtt_entries; | |
| 46 | ||
| 47 | We end up with -1 in gtt_entries. | |
| 48 | ||
| 49 | This leads to intel_i915_configure reading/writing to areas outside of | |
| 50 | mapped memory and the oops. | |
| 51 | ||
| 52 | Signed-off-by: Brandon Philips <bphilips@suse.de> | |
| 53 | Acked-by: Thomas Renninger <trenn@suse.de> | |
| 54 | ||
| 55 | --- | |
| 56 | drivers/char/agp/intel-agp.c | 7 +++++++ | |
| 57 | 1 file changed, 7 insertions(+) | |
| 58 | ||
| 59 | --- a/drivers/char/agp/intel-agp.c | |
| 60 | +++ b/drivers/char/agp/intel-agp.c | |
| 61 | @@ -564,6 +564,13 @@ static void intel_i830_init_gtt_entries( | |
| 62 | } else { | |
| 63 | switch (gmch_ctrl & I855_GMCH_GMS_MASK) { | |
| 64 | case I855_GMCH_GMS_STOLEN_1M: | |
| 65 | + if (IS_G33) { | |
| 66 | + size = 0; | |
| 67 | + printk(KERN_WARNING PFX | |
| 68 | + "Warning: G33 chipset with 1MB" | |
| 69 | + " allocated. Older X.org Intel drivers" | |
| 70 | + " will not work.\n"); | |
| 71 | + } | |
| 72 | gtt_entries = MB(1) - KB(size); | |
| 73 | break; | |
| 74 | case I855_GMCH_GMS_STOLEN_4M: |