diff options
Diffstat (limited to 'drivers/gpu/drm/nouveau/nvkm/engine/device/base.c')
| -rw-r--r-- | drivers/gpu/drm/nouveau/nvkm/engine/device/base.c | 39 |
1 files changed, 26 insertions, 13 deletions
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c index dcb70677d0ac..7851bec5f0e5 100644 --- a/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c @@ -2924,17 +2924,34 @@ nvkm_device_del(struct nvkm_device **pdevice) } } +/* returns true if the GPU is in the CPU native byte order */ static inline bool nvkm_device_endianness(struct nvkm_device *device) { - u32 boot1 = nvkm_rd32(device, 0x000004) & 0x01000001; #ifdef __BIG_ENDIAN - if (!boot1) - return false; + const bool big_endian = true; #else - if (boot1) - return false; + const bool big_endian = false; #endif + + /* Read NV_PMC_BOOT_1, and assume non-functional endian switch if it + * doesn't contain the expected values. + */ + u32 pmc_boot_1 = nvkm_rd32(device, 0x000004); + if (pmc_boot_1 && pmc_boot_1 != 0x01000001) + return !big_endian; /* Assume GPU is LE in this case. */ + + /* 0 means LE and 0x01000001 means BE GPU. Condition is true when + * GPU/CPU endianness don't match. + */ + if (big_endian == !pmc_boot_1) { + nvkm_wr32(device, 0x000004, 0x01000001); + nvkm_rd32(device, 0x000000); + if (nvkm_rd32(device, 0x000004) != (big_endian ? 0x01000001 : 0x00000000)) + return !big_endian; /* Assume GPU is LE on any unexpected read-back. */ + } + + /* CPU/GPU endianness should (hopefully) match. */ return true; } @@ -2987,14 +3004,10 @@ nvkm_device_ctor(const struct nvkm_device_func *func, if (detect) { /* switch mmio to cpu's native endianness */ if (!nvkm_device_endianness(device)) { - nvkm_wr32(device, 0x000004, 0x01000001); - nvkm_rd32(device, 0x000000); - if (!nvkm_device_endianness(device)) { - nvdev_error(device, - "GPU not supported on big-endian\n"); - ret = -ENOSYS; - goto done; - } + nvdev_error(device, + "Couldn't switch GPU to CPUs endianess\n"); + ret = -ENOSYS; + goto done; } boot0 = nvkm_rd32(device, 0x000000); |