From: Jan Vesely Date: Thu, 9 Apr 2015 01:34:36 +0000 (-0400) Subject: drm/nouveau/bios: fix fetching from acpi on certain systems X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4195f40685a5f2783b4decece13ed740b61ee038;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git drm/nouveau/bios: fix fetching from acpi on certain systems nvbios_extend() returns 1 to indicate "extended the array" and 0 to indicate the array is already big enough. This is used by the core shadowing code to prevent re-fetching chunks of the image that have already been shadowed. The ACPI fetching code may possibly need to extend this further due to requiring fetches to happen in 4KiB chunks. Under certain circumstances (that happen if the total image size is a multiple of 4KiB), the memory allocated to store the shadow will already be big enough, causing the ACPI code's nvbios_extend() call to return 0, which is misinterpreted as a failure. The fix is simple, accept >= 0 as a successful condition here. The core will have already made sure that we're not re-fetching data we already have. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89047 v2 (Ben Skeggs): - dropped hunk which would cause unnecessary re-fetching - more descriptive explanation Signed-off-by: Jan Vesely Signed-off-by: Ben Skeggs --- diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowacpi.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowacpi.c index 1fbd93bbb561..f9d0eb5647fa 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowacpi.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowacpi.c @@ -52,7 +52,7 @@ acpi_read_fast(void *data, u32 offset, u32 length, struct nvkm_bios *bios) u32 start = offset & ~0x00000fff; u32 fetch = limit - start; - if (nvbios_extend(bios, limit) > 0) { + if (nvbios_extend(bios, limit) >= 0) { int ret = nouveau_acpi_get_bios_chunk(bios->data, start, fetch); if (ret == fetch) return fetch; @@ -73,7 +73,7 @@ acpi_read_slow(void *data, u32 offset, u32 length, struct nvkm_bios *bios) u32 start = offset & ~0xfff; u32 fetch = 0; - if (nvbios_extend(bios, limit) > 0) { + if (nvbios_extend(bios, limit) >= 0) { while (start + fetch < limit) { int ret = nouveau_acpi_get_bios_chunk(bios->data, start + fetch,