drm/xe/oa: Allow reading after disabling OA stream

commit 9be6fd9fbd2032b683e51374497768af9aaa228a upstream.

Some OA data might be present in the OA buffer when OA stream is
disabled. Allow UMD's to retrieve this data, so that all data till the
point when OA stream is disabled can be retrieved.

v2: Update tail pointer after disable (Umesh)

Fixes: efb315d0a013 ("drm/xe/oa/uapi: Read file_operation")
Cc: stable@vger.kernel.org
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Umesh Nerlige Ramappa<umesh.nerlige.ramappa@intel.com>
Link: https://patch.msgid.link/20260313053630.3176100-1-ashutosh.dixit@intel.com
(cherry picked from commit 4ff57c5e8dbba23b5457be12f9709d5c016da16e)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c
index 3f142f95e5d4978998f0da76a9e7b91f908ab0d0..fe997494a6f996fbd97f41716e7a65217a2255cc 100644 (file)
--- a/drivers/gpu/drm/xe/xe_oa.c
+++ b/drivers/gpu/drm/xe/xe_oa.c
@@ -520,8 +520,7 @@ static ssize_t xe_oa_read(struct file *file, char __user *buf,
        size_t offset = 0;
        int ret;
 
-       /* Can't read from disabled streams */
-       if (!stream->enabled || !stream->sample)
+       if (!stream->sample)
                return -EINVAL;
 
        if (!(file->f_flags & O_NONBLOCK)) {
@@ -1375,6 +1374,10 @@ static void xe_oa_stream_disable(struct xe_oa_stream *stream)
 
        if (stream->sample)
                hrtimer_cancel(&stream->poll_check_timer);
+
+       /* Update stream->oa_buffer.tail to allow any final reports to be read */
+       if (xe_oa_buffer_check_unlocked(stream))
+               wake_up(&stream->poll_wq);
 }
 
 static int xe_oa_enable_preempt_timeslice(struct xe_oa_stream *stream)