[PATCH v1 7/7] media: chips-media: wave5: Resume device before setting EOS flag

["Jackson.lee" <jackson.lee@chipsnmedia.com>]

From: Jackson Lee <jackson.lee@chipsnmedia.com>

Setting the EOS flag talks to the firmware via send_firmware_command(),
which accesses VPU registers. Both the STREAMOFF path
(wave5_vpu_dec_job_abort()) and the V4L2_DEC_CMD_STOP path
(wave5_vpu_dec_stop()) can run while the device is runtime suspended, so
those register accesses hit powered-down hardware and the SoC raises an
asynchronous SError, panicking the kernel:

  SError Interrupt on CPU3, code 0x00000000bf000000 -- SError
   send_firmware_command+0x2c/0x160 [wave5]
   wave5_vpu_dec_set_bitstream_flag+0x6c/0x80 [wave5]
   wave5_vpu_dec_update_bitstream_buffer+0x80/0xec [wave5]
   wave5_vpu_dec_job_abort+0x44/0xa0 [wave5]
   v4l2_m2m_cancel_job+0x110/0x19c [v4l2_mem2mem]
   v4l2_m2m_streamoff+0x24/0x140 [v4l2_mem2mem]

Resume the device with pm_runtime_resume_and_get() around the EOS
firmware command and release it with pm_runtime_put_autosuspend(),
matching the runtime PM handling already done in
wave5_vpu_dec_device_run().

Fixes: 9707a6254a8a ("media: chips-media: wave5: Add the v4l2 layer")
Cc: stable@vger.kernel.org
Signed-off-by: Jackson Lee <jackson.lee@chipsnmedia.com>
Signed-off-by: Nas Chung <nas.chung@chipsnmedia.com>
---
 .../chips-media/wave5/wave5-vpu-dec.c         | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
index 1817b83c5884..6564cf3ec739 100644
--- a/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
+++ b/drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c
@@ -823,7 +823,15 @@ static int wave5_vpu_dec_stop(struct vpu_instance *inst)
 		 * calls do not block on a mutex while inside this spinlock.
 		 */
 		spin_unlock_irqrestore(&inst->state_spinlock, flags);
+		/*
+		 * V4L2_DEC_CMD_STOP can arrive while the device is runtime
+		 * suspended (e.g. on pipeline teardown). Setting the EOS flag
+		 * accesses VPU registers via send_firmware_command(), so the
+		 * device must be resumed first to avoid an asynchronous SError.
+		 */
+		pm_runtime_resume_and_get(inst->dev->dev);
 		ret = wave5_vpu_dec_set_eos_on_firmware(inst);
+		pm_runtime_put_autosuspend(inst->dev->dev);
 		if (ret)
 			return ret;
 
@@ -1797,11 +1805,22 @@ static void wave5_vpu_dec_job_abort(void *priv)
 	if (ret)
 		return;
 
+	/*
+	 * job_abort() runs from the STREAMOFF path and may be called while the
+	 * device is runtime suspended. Setting the EOS flag talks to the
+	 * firmware (send_firmware_command() accesses VPU registers), so the
+	 * device must be resumed first; otherwise the register access faults
+	 * with an asynchronous SError.
+	 */
+	pm_runtime_resume_and_get(inst->dev->dev);
+
 	ret = wave5_vpu_dec_set_eos_on_firmware(inst);
 	if (ret)
 		dev_warn(inst->dev->dev,
 			 "Setting EOS for the bitstream, fail: %d\n", ret);
 
+	pm_runtime_put_autosuspend(inst->dev->dev);
+
 	v4l2_m2m_job_finish(inst->v4l2_m2m_dev, m2m_ctx);
 }
 
-- 
2.43.0