amdgpu_device_get_job_timeout_settings() passes a pointer directly
to the global amdgpu_lockup_timeout[] buffer into strsep().
strsep() destructively replaces delimiter characters with '\0'
in-place.

On multi-GPU systems, this function is called once per device.
When a multi-value setting like "0,0,0,-1" is used, the first
GPU's call transforms the global buffer into "0\00\00\0-1". The
second GPU then sees only "0" (terminated at the first '\0'),
parses a single value, hits the single-value fallthrough
(index == 1), and applies timeout=0 to all rings — causing
immediate false job timeouts.

Fix this by copying into a stack-local array before calling
strsep(), so the global module parameter buffer remains intact
across calls. The buffer is AMDGPU_MAX_TIMEOUT_PARAM_LENGTH
(256) bytes, which is safe for the stack.

v2: wrap commit message to 72 columns, add Assisted-by tag.
v3: use stack array with strscpy() instead of kstrdup()/kfree()
    to avoid unnecessary heap allocation (Christian).

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Ruijing Dong <[email protected]>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index dcae77b6c272..fbe553c38583 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3498,7 +3498,8 @@ static void amdgpu_device_xgmi_reset_func(struct 
work_struct *__work)
 
 static int amdgpu_device_get_job_timeout_settings(struct amdgpu_device *adev)
 {
-       char *input = amdgpu_lockup_timeout;
+       char buf[AMDGPU_MAX_TIMEOUT_PARAM_LENGTH];
+       char *input = buf;
        char *timeout_setting = NULL;
        int index = 0;
        long timeout;
@@ -3508,9 +3509,17 @@ static int amdgpu_device_get_job_timeout_settings(struct 
amdgpu_device *adev)
        adev->gfx_timeout = adev->compute_timeout = adev->sdma_timeout =
                adev->video_timeout = msecs_to_jiffies(2000);
 
-       if (!strnlen(input, AMDGPU_MAX_TIMEOUT_PARAM_LENGTH))
+       if (!strnlen(amdgpu_lockup_timeout, AMDGPU_MAX_TIMEOUT_PARAM_LENGTH))
                return 0;
 
+       /*
+        * strsep() destructively modifies its input by replacing delimiters
+        * with '\0'. Use a stack copy so the global module parameter buffer
+        * remains intact for multi-GPU systems where this function is called
+        * once per device.
+        */
+       strscpy(buf, amdgpu_lockup_timeout, sizeof(buf));
+
        while ((timeout_setting = strsep(&input, ",")) &&
               strnlen(timeout_setting, AMDGPU_MAX_TIMEOUT_PARAM_LENGTH)) {
                ret = kstrtol(timeout_setting, 0, &timeout);
-- 
2.49.0.593.gd86a19f485

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