[PATCH 2/2] accel/ethosu: fix wrong weight index in NPU_SET_SCALE1_LENGTH on U85

[Muhammad Bilal <meatuni001@gmail.com>]

On non-U65 hardware (e.g. U85), opcode 0x4093 is NPU_SET_WEIGHT2_LENGTH.
The BASE handler for the same opcode correctly assigns to
st.weight[2].base, but the LENGTH handler mistakenly assigns cmds[1]
to st.weight[1].length instead of st.weight[2].length.

This leaves weight[2].length at its initialised sentinel value of
0xffffffff and corrupts weight[1].length with the user-supplied value,
breaking the software bounds-check state for both weight buffers on U85.

Fix the index to match the BASE handler.

Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
---
 drivers/accel/ethosu/ethosu_gem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/accel/ethosu/ethosu_gem.c b/drivers/accel/ethosu/ethosu_gem.c
index 043541407a8f..5a02285a4986 100644
--- a/drivers/accel/ethosu/ethosu_gem.c
+++ b/drivers/accel/ethosu/ethosu_gem.c
@@ -600,7 +600,7 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev,
 			if (ethosu_is_u65(edev))
 				st.scale[1].length = cmds[1];
 			else
-				st.weight[1].length = cmds[1];
+				st.weight[2].length = cmds[1];
 			break;
 		case NPU_SET_WEIGHT3_BASE:
 			st.weight[3].base = addr;
-- 
2.53.0