From 1c2d7a656655a50bd1b7227fb26d173959a1955d Mon Sep 17 00:00:00 2001 From: Qiang Yu Date: Tue, 26 May 2026 14:45:48 +0800 Subject: [PATCH] drm/amdgpu: initialize iter.start in amdgpu_devcoredump_format This fixes read /sys/class/drm/cardN/device/devcoredump/data return empty content sometimes. amdgpu_devcoredump_format() leaves struct drm_print_iterator's .start field uninitialized on the stack before passing it to drm_coredump_printer(). __drm_puts_coredump() compares the running .offset against .start to decide whether to skip or copy each chunk: if (iterator->offset < iterator->start) { if (iterator->offset + len <= iterator->start) { iterator->offset += len; return; } ... } Fixes: 4bbba79a7f1d ("drm/amdgpu: move devcoredump generation to a worker") Acked-by: Alex Deucher Signed-off-by: Qiang Yu Signed-off-by: Alex Deucher (cherry picked from commit cd6397b7af8262a380e188dc32e9de11ff897ed2) --- drivers/gpu/drm/amd/amdgpu/amdgpu_dev_coredump.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dev_coredump.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dev_coredump.c index 27830518a230..bed68f0c3080 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dev_coredump.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dev_coredump.c @@ -229,6 +229,7 @@ amdgpu_devcoredump_format(char *buffer, size_t count, struct amdgpu_coredump_inf sizing_pass = buffer == NULL; iter.data = buffer; + iter.start = 0; iter.offset = 0; iter.remain = count;