SDMA v3-v5 can copy almost 4 MiB in a single copy operation.
Use the same value as PAL and Mesa for copy_max_bytes.
For reference, see oss2DmaCmdBuffer.cpp in PAL:
"Due to HW limitation, the maximum count may not be 2^n-1,
can only be 2^n - 1 - start_addr[4:2]"
See also sid.h in Mesa:
"There is apparently an undocumented HW limitation that
prevents the HW from copying the last 255 bytes of (1 << 22) - 1"
Fixes: dfe5c2b76b2a ("drm/amdgpu: Correct bytes limit for SDMA 3.0 copy and
fill")
Signed-off-by: Timur Kristóf <[email protected]>
---
drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
b/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
index 1c076bd1cf73..9302cf0b5e4b 100644
--- a/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c
@@ -1659,11 +1659,11 @@ static void sdma_v3_0_emit_fill_buffer(struct amdgpu_ib
*ib,
}
static const struct amdgpu_buffer_funcs sdma_v3_0_buffer_funcs = {
- .copy_max_bytes = 0x3fffe0, /* not 0x3fffff due to HW limitation */
+ .copy_max_bytes = 0x3fff00, /* not 0x3fffff due to HW limitation */
.copy_num_dw = 7,
.emit_copy_buffer = sdma_v3_0_emit_copy_buffer,
- .fill_max_bytes = 0x3fffe0, /* not 0x3fffff due to HW limitation */
+ .fill_max_bytes = 0x3fff00, /* not 0x3fffff due to HW limitation */
.fill_num_dw = 5,
.emit_fill_buffer = sdma_v3_0_emit_fill_buffer,
};
--
2.51.0
