[Intel-gfx] [PATCH 45/51] drm/gm12u320: Simplify upload work

Hans de Goede hdegoede at redhat.com
Thu Feb 27 19:04:07 UTC 2020


Hi,

On 2/27/20 7:15 PM, Daniel Vetter wrote:
> Instead of having a work item that never stops (which really should be
> a kthread), with a dedicated workqueue to not upset anyone else, use a
> delayed work. A bunch of changes:
> 
> - We can throw out all the custom wakeup and requeue logic and state
>    tracking. If we schedule the work with a 0 delay it'll get
>    scheduled immediately.
> 
> - Persistent state (frame & draw_status_timeout) need to be moved out
>    of the work.
> 
> - diff is bigger than the changes, biggest chunk is reindenting the
>    work fn because it lost its while loop.
> 
> Lots of code deleting as consequence all over. Specifically we can
> delete the drm_driver.release code now!
> 
> v2: Review from Hans:
> - Use mod_delayed_work in the plane update path to make sure we do
>    actually schedule immediately). In the worker we still want
>    queue_delayed_work, which won't modify the timeout when the work is
>    already scheduled. Which is exactly what we want if the work races
>    with a plane update.
> - Switch to system_long_wq, Hans says on usb2 a plane upload can take
>    80 ms.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Hans de Goede <hdegoede at redhat.com>
> Cc: "Noralf Trønnes" <noralf at tronnes.org>

Patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede at redhat.com>

Regards,

Hans


> ---
>   drivers/gpu/drm/tiny/gm12u320.c | 171 +++++++++++++-------------------
>   1 file changed, 68 insertions(+), 103 deletions(-)
> 
> diff --git a/drivers/gpu/drm/tiny/gm12u320.c b/drivers/gpu/drm/tiny/gm12u320.c
> index c22b2ee470eb..bbc4ef4456e6 100644
> --- a/drivers/gpu/drm/tiny/gm12u320.c
> +++ b/drivers/gpu/drm/tiny/gm12u320.c
> @@ -89,13 +89,12 @@ struct gm12u320_device {
>   	unsigned char                   *cmd_buf;
>   	unsigned char                   *data_buf[GM12U320_BLOCK_COUNT];
>   	struct {
> -		bool                     run;
> -		struct workqueue_struct *workq;
> -		struct work_struct       work;
> -		wait_queue_head_t        waitq;
> +		struct delayed_work       work;
>   		struct mutex             lock;
>   		struct drm_framebuffer  *fb;
>   		struct drm_rect          rect;
> +		int frame;
> +		int draw_status_timeout;
>   	} fb_update;
>   };
>   
> @@ -183,19 +182,9 @@ static int gm12u320_usb_alloc(struct gm12u320_device *gm12u320)
>   		       data_block_footer, DATA_BLOCK_FOOTER_SIZE);
>   	}
>   
> -	gm12u320->fb_update.workq = create_singlethread_workqueue(DRIVER_NAME);
> -	if (!gm12u320->fb_update.workq)
> -		return -ENOMEM;
> -
>   	return 0;
>   }
>   
> -static void gm12u320_usb_free(struct gm12u320_device *gm12u320)
> -{
> -	if (gm12u320->fb_update.workq)
> -		destroy_workqueue(gm12u320->fb_update.workq);
> -}
> -
>   static int gm12u320_misc_request(struct gm12u320_device *gm12u320,
>   				 u8 req_a, u8 req_b,
>   				 u8 arg_a, u8 arg_b, u8 arg_c, u8 arg_d)
> @@ -338,80 +327,77 @@ static void gm12u320_copy_fb_to_blocks(struct gm12u320_device *gm12u320)
>   static void gm12u320_fb_update_work(struct work_struct *work)
>   {
>   	struct gm12u320_device *gm12u320 =
> -		container_of(work, struct gm12u320_device, fb_update.work);
> -	int draw_status_timeout = FIRST_FRAME_TIMEOUT;
> +		container_of(to_delayed_work(work), struct gm12u320_device,
> +			     fb_update.work);
>   	int block, block_size, len;
> -	int frame = 0;
>   	int ret = 0;
>   
> -	while (gm12u320->fb_update.run) {
> -		gm12u320_copy_fb_to_blocks(gm12u320);
> -
> -		for (block = 0; block < GM12U320_BLOCK_COUNT; block++) {
> -			if (block == GM12U320_BLOCK_COUNT - 1)
> -				block_size = DATA_LAST_BLOCK_SIZE;
> -			else
> -				block_size = DATA_BLOCK_SIZE;
> -
> -			/* Send data command to device */
> -			memcpy(gm12u320->cmd_buf, cmd_data, CMD_SIZE);
> -			gm12u320->cmd_buf[8] = block_size & 0xff;
> -			gm12u320->cmd_buf[9] = block_size >> 8;
> -			gm12u320->cmd_buf[20] = 0xfc - block * 4;
> -			gm12u320->cmd_buf[21] = block | (frame << 7);
> -
> -			ret = usb_bulk_msg(gm12u320->udev,
> -				usb_sndbulkpipe(gm12u320->udev, DATA_SND_EPT),
> -				gm12u320->cmd_buf, CMD_SIZE, &len,
> -				CMD_TIMEOUT);
> -			if (ret || len != CMD_SIZE)
> -				goto err;
> -
> -			/* Send data block to device */
> -			ret = usb_bulk_msg(gm12u320->udev,
> -				usb_sndbulkpipe(gm12u320->udev, DATA_SND_EPT),
> -				gm12u320->data_buf[block], block_size,
> -				&len, DATA_TIMEOUT);
> -			if (ret || len != block_size)
> -				goto err;
> -
> -			/* Read status */
> -			ret = usb_bulk_msg(gm12u320->udev,
> -				usb_rcvbulkpipe(gm12u320->udev, DATA_RCV_EPT),
> -				gm12u320->cmd_buf, READ_STATUS_SIZE, &len,
> -				CMD_TIMEOUT);
> -			if (ret || len != READ_STATUS_SIZE)
> -				goto err;
> -		}
> +	gm12u320_copy_fb_to_blocks(gm12u320);
> +
> +	for (block = 0; block < GM12U320_BLOCK_COUNT; block++) {
> +		if (block == GM12U320_BLOCK_COUNT - 1)
> +			block_size = DATA_LAST_BLOCK_SIZE;
> +		else
> +			block_size = DATA_BLOCK_SIZE;
> +
> +		/* Send data command to device */
> +		memcpy(gm12u320->cmd_buf, cmd_data, CMD_SIZE);
> +		gm12u320->cmd_buf[8] = block_size & 0xff;
> +		gm12u320->cmd_buf[9] = block_size >> 8;
> +		gm12u320->cmd_buf[20] = 0xfc - block * 4;
> +		gm12u320->cmd_buf[21] =
> +			block | (gm12u320->fb_update.frame << 7);
>   
> -		/* Send draw command to device */
> -		memcpy(gm12u320->cmd_buf, cmd_draw, CMD_SIZE);
>   		ret = usb_bulk_msg(gm12u320->udev,
>   			usb_sndbulkpipe(gm12u320->udev, DATA_SND_EPT),
> -			gm12u320->cmd_buf, CMD_SIZE, &len, CMD_TIMEOUT);
> +			gm12u320->cmd_buf, CMD_SIZE, &len,
> +			CMD_TIMEOUT);
>   		if (ret || len != CMD_SIZE)
>   			goto err;
>   
> +		/* Send data block to device */
> +		ret = usb_bulk_msg(gm12u320->udev,
> +			usb_sndbulkpipe(gm12u320->udev, DATA_SND_EPT),
> +			gm12u320->data_buf[block], block_size,
> +			&len, DATA_TIMEOUT);
> +		if (ret || len != block_size)
> +			goto err;
> +
>   		/* Read status */
>   		ret = usb_bulk_msg(gm12u320->udev,
>   			usb_rcvbulkpipe(gm12u320->udev, DATA_RCV_EPT),
>   			gm12u320->cmd_buf, READ_STATUS_SIZE, &len,
> -			draw_status_timeout);
> +			CMD_TIMEOUT);
>   		if (ret || len != READ_STATUS_SIZE)
>   			goto err;
> -
> -		draw_status_timeout = CMD_TIMEOUT;
> -		frame = !frame;
> -
> -		/*
> -		 * We must draw a frame every 2s otherwise the projector
> -		 * switches back to showing its logo.
> -		 */
> -		wait_event_timeout(gm12u320->fb_update.waitq,
> -				   !gm12u320->fb_update.run ||
> -					gm12u320->fb_update.fb != NULL,
> -				   IDLE_TIMEOUT);
>   	}
> +
> +	/* Send draw command to device */
> +	memcpy(gm12u320->cmd_buf, cmd_draw, CMD_SIZE);
> +	ret = usb_bulk_msg(gm12u320->udev,
> +		usb_sndbulkpipe(gm12u320->udev, DATA_SND_EPT),
> +		gm12u320->cmd_buf, CMD_SIZE, &len, CMD_TIMEOUT);
> +	if (ret || len != CMD_SIZE)
> +		goto err;
> +
> +	/* Read status */
> +	ret = usb_bulk_msg(gm12u320->udev,
> +		usb_rcvbulkpipe(gm12u320->udev, DATA_RCV_EPT),
> +		gm12u320->cmd_buf, READ_STATUS_SIZE, &len,
> +		gm12u320->fb_update.draw_status_timeout);
> +	if (ret || len != READ_STATUS_SIZE)
> +		goto err;
> +
> +	gm12u320->fb_update.draw_status_timeout = CMD_TIMEOUT;
> +	gm12u320->fb_update.frame = !gm12u320->fb_update.frame;
> +
> +	/*
> +	 * We must draw a frame every 2s otherwise the projector
> +	 * switches back to showing its logo.
> +	 */
> +	queue_delayed_work(system_long_wq, &gm12u320->fb_update.work,
> +			   IDLE_TIMEOUT);
> +
>   	return;
>   err:
>   	/* Do not log errors caused by module unload or device unplug */
> @@ -446,36 +432,24 @@ static void gm12u320_fb_mark_dirty(struct drm_framebuffer *fb,
>   	mutex_unlock(&gm12u320->fb_update.lock);
>   
>   	if (wakeup)
> -		wake_up(&gm12u320->fb_update.waitq);
> +		mod_delayed_work(system_long_wq, &gm12u320->fb_update.work, 0);
>   
>   	if (old_fb)
>   		drm_framebuffer_put(old_fb);
>   }
>   
> -static void gm12u320_start_fb_update(struct gm12u320_device *gm12u320)
> -{
> -	mutex_lock(&gm12u320->fb_update.lock);
> -	gm12u320->fb_update.run = true;
> -	mutex_unlock(&gm12u320->fb_update.lock);
> -
> -	queue_work(gm12u320->fb_update.workq, &gm12u320->fb_update.work);
> -}
> -
>   static void gm12u320_stop_fb_update(struct gm12u320_device *gm12u320)
>   {
> -	mutex_lock(&gm12u320->fb_update.lock);
> -	gm12u320->fb_update.run = false;
> -	mutex_unlock(&gm12u320->fb_update.lock);
> +	struct drm_framebuffer *old_fb;
>   
> -	wake_up(&gm12u320->fb_update.waitq);
> -	cancel_work_sync(&gm12u320->fb_update.work);
> +	cancel_delayed_work_sync(&gm12u320->fb_update.work);
>   
>   	mutex_lock(&gm12u320->fb_update.lock);
> -	if (gm12u320->fb_update.fb) {
> -		drm_framebuffer_put(gm12u320->fb_update.fb);
> -		gm12u320->fb_update.fb = NULL;
> -	}
> +	old_fb = gm12u320->fb_update.fb;
> +	gm12u320->fb_update.fb = NULL;
>   	mutex_unlock(&gm12u320->fb_update.lock);
> +
> +	drm_framebuffer_put(old_fb);
>   }
>   
>   static int gm12u320_set_ecomode(struct gm12u320_device *gm12u320)
> @@ -583,11 +557,11 @@ static void gm12u320_pipe_enable(struct drm_simple_display_pipe *pipe,
>   				 struct drm_crtc_state *crtc_state,
>   				 struct drm_plane_state *plane_state)
>   {
> -	struct gm12u320_device *gm12u320 = pipe->crtc.dev->dev_private;
>   	struct drm_rect rect = { 0, 0, GM12U320_USER_WIDTH, GM12U320_HEIGHT };
> +	struct gm12u320_device *gm12u320 = pipe->crtc.dev->dev_private;
>   
> +	gm12u320->fb_update.draw_status_timeout = FIRST_FRAME_TIMEOUT;
>   	gm12u320_fb_mark_dirty(plane_state->fb, &rect);
> -	gm12u320_start_fb_update(gm12u320);
>   }
>   
>   static void gm12u320_pipe_disable(struct drm_simple_display_pipe *pipe)
> @@ -622,13 +596,6 @@ static const uint64_t gm12u320_pipe_modifiers[] = {
>   	DRM_FORMAT_MOD_INVALID
>   };
>   
> -static void gm12u320_driver_release(struct drm_device *dev)
> -{
> -	struct gm12u320_device *gm12u320 = dev->dev_private;
> -
> -	gm12u320_usb_free(gm12u320);
> -}
> -
>   DEFINE_DRM_GEM_FOPS(gm12u320_fops);
>   
>   static struct drm_driver gm12u320_drm_driver = {
> @@ -640,7 +607,6 @@ static struct drm_driver gm12u320_drm_driver = {
>   	.major		 = DRIVER_MAJOR,
>   	.minor		 = DRIVER_MINOR,
>   
> -	.release	 = gm12u320_driver_release,
>   	.fops		 = &gm12u320_fops,
>   	DRM_GEM_SHMEM_DRIVER_OPS,
>   };
> @@ -670,9 +636,8 @@ static int gm12u320_usb_probe(struct usb_interface *interface,
>   		return -ENOMEM;
>   
>   	gm12u320->udev = interface_to_usbdev(interface);
> -	INIT_WORK(&gm12u320->fb_update.work, gm12u320_fb_update_work);
> +	INIT_DELAYED_WORK(&gm12u320->fb_update.work, gm12u320_fb_update_work);
>   	mutex_init(&gm12u320->fb_update.lock);
> -	init_waitqueue_head(&gm12u320->fb_update.waitq);
>   
>   	dev = &gm12u320->dev;
>   	ret = devm_drm_dev_init(&interface->dev, dev, &gm12u320_drm_driver);
> 



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