Commit 017ef122 authored by Shuicheng Lin's avatar Shuicheng Lin Committed by Matthew Brost
Browse files

drm/xe: Release runtime pm for error path of xe_devcoredump_read() 



xe_pm_runtime_put() is missed to be called for the error path in
xe_devcoredump_read().
Add function description comments for xe_devcoredump_read() to help
understand it.

v2: more detail function comments and refine goto logic (Matt)

Fixes: c4a2e5f8 ("drm/xe: Add devcoredump chunking")
Cc: stable@vger.kernel.org
Reviewed-by: default avatarMatthew Brost <matthew.brost@intel.com>
Signed-off-by: default avatarShuicheng Lin <shuicheng.lin@intel.com>
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250707004911.3502904-6-shuicheng.lin@intel.com
parent 8ce560d8

drivers/gpu/drm/xe/xe_devcoredump.c

+28 −10
Original line number Diff line number Diff line
@@ -171,14 +171,32 @@ static void xe_devcoredump_snapshot_free(struct xe_devcoredump_snapshot *ss) 


#define XE_DEVCOREDUMP_CHUNK_MAX	(SZ_512M + SZ_1G)



/**

 * xe_devcoredump_read() - Read data from the Xe device coredump snapshot

 * @buffer: Destination buffer to copy the coredump data into

 * @offset: Offset in the coredump data to start reading from

 * @count: Number of bytes to read

 * @data: Pointer to the xe_devcoredump structure

 * @datalen: Length of the data (unused)

 *

 * Reads a chunk of the coredump snapshot data into the provided buffer.

 * If the devcoredump is smaller than 1.5 GB (XE_DEVCOREDUMP_CHUNK_MAX),

 * it is read directly from a pre-written buffer. For larger devcoredumps,

 * the pre-written buffer must be periodically repopulated from the snapshot

 * state due to kmalloc size limitations.

 *

 * Return: Number of bytes copied on success, or a negative error code on failure.

 */

static ssize_t xe_devcoredump_read(char *buffer, loff_t offset,

				   size_t count, void *data, size_t datalen)

{

	struct xe_devcoredump *coredump = data;

	struct xe_devcoredump_snapshot *ss;

	ssize_t byte_copied;

	ssize_t byte_copied = 0;

	u32 chunk_offset;

	ssize_t new_chunk_position;

	bool pm_needed = false;

	int ret = 0;



	if (!coredump)

		return -ENODEV;
@@ -188,20 +206,19 @@ static ssize_t xe_devcoredump_read(char *buffer, loff_t offset, 
	/* Ensure delayed work is captured before continuing */

	flush_work(&ss->work);



	if (ss->read.size > XE_DEVCOREDUMP_CHUNK_MAX)

	pm_needed = ss->read.size > XE_DEVCOREDUMP_CHUNK_MAX;

	if (pm_needed)

		xe_pm_runtime_get(gt_to_xe(ss->gt));



	mutex_lock(&coredump->lock);



	if (!ss->read.buffer) {

		mutex_unlock(&coredump->lock);

		return -ENODEV;

		ret = -ENODEV;

		goto unlock;

	}



	if (offset >= ss->read.size) {

		mutex_unlock(&coredump->lock);

		return 0;

	}

	if (offset >= ss->read.size)

		goto unlock;



	new_chunk_position = div_u64_rem(offset,

					 XE_DEVCOREDUMP_CHUNK_MAX,
@@ -221,12 +238,13 @@ static ssize_t xe_devcoredump_read(char *buffer, loff_t offset, 
		ss->read.size - offset;

	memcpy(buffer, ss->read.buffer + chunk_offset, byte_copied);



unlock:

	mutex_unlock(&coredump->lock);



	if (ss->read.size > XE_DEVCOREDUMP_CHUNK_MAX)

	if (pm_needed)

		xe_pm_runtime_put(gt_to_xe(ss->gt));



	return byte_copied;

	return byte_copied ? byte_copied : ret;

}



static void xe_devcoredump_free(void *data)