diff mbox series

[v2,12/23] media: rkvdec: Stop overclocking the decoder

Message ID 20220331193726.289559-13-nicolas.dufresne@collabora.com (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Nicolas Dufresne March 31, 2022, 7:37 p.m. UTC 
While this overclock hack seems to work on some implementations
(some ChromeBooks, RockPi4) it also causes instability on other
implementations (notably LibreComputer Renegade, but there were more
reports in the LibreELEC project, where this has been removed). While
performance is indeed affected (tested with GStreamer), 4K playback
still works as long as you don't operate in lock step and keep at
least 1 frame ahead of time in the decode queue.

After discussion with ChromeOS members, it would seem that their
implementation indeed used to synchronously decode each frames, so
this hack was simply compensating for their code being less
efficient. In my opinion, this hack should not have been included
upstream.

Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Sebastian Fricke <sebastian.fricke@collabora.com>
---
 drivers/staging/media/rkvdec/rkvdec.c | 6 ------
 1 file changed, 6 deletions(-)

Comments

Ezequiel Garcia April 2, 2022, 11:05 a.m. UTC | #1 
On Thu, Mar 31, 2022 at 03:37:14PM -0400, Nicolas Dufresne wrote:
> While this overclock hack seems to work on some implementations
> (some ChromeBooks, RockPi4) it also causes instability on other
> implementations (notably LibreComputer Renegade, but there were more
> reports in the LibreELEC project, where this has been removed). While
> performance is indeed affected (tested with GStreamer), 4K playback
> still works as long as you don't operate in lock step and keep at
> least 1 frame ahead of time in the decode queue.
> 
> After discussion with ChromeOS members, it would seem that their
> implementation indeed used to synchronously decode each frames, so
> this hack was simply compensating for their code being less
> efficient. In my opinion, this hack should not have been included
> upstream.
> 
> Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
> Reviewed-by: Sebastian Fricke <sebastian.fricke@collabora.com>

Fixes: cd33c830448ba ("media: rkvdec: Add the rkvdec driver")
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

Thanks,
Ezequiel

> ---
>  drivers/staging/media/rkvdec/rkvdec.c | 6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/drivers/staging/media/rkvdec/rkvdec.c b/drivers/staging/media/rkvdec/rkvdec.c
> index c0cf3488f970..2df8cf4883e2 100644
> --- a/drivers/staging/media/rkvdec/rkvdec.c
> +++ b/drivers/staging/media/rkvdec/rkvdec.c
> @@ -1027,12 +1027,6 @@ static int rkvdec_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	/*
> -	 * Bump ACLK to max. possible freq. (500 MHz) to improve performance
> -	 * When 4k video playback.
> -	 */
> -	clk_set_rate(rkvdec->clocks[0].clk, 500 * 1000 * 1000);
> -
>  	rkvdec->regs = devm_platform_ioremap_resource(pdev, 0);
>  	if (IS_ERR(rkvdec->regs))
>  		return PTR_ERR(rkvdec->regs);
> -- 
> 2.34.1
>
diff mbox series

Patch

diff --git a/drivers/staging/media/rkvdec/rkvdec.c b/drivers/staging/media/rkvdec/rkvdec.c
index c0cf3488f970..2df8cf4883e2 100644
--- a/drivers/staging/media/rkvdec/rkvdec.c
+++ b/drivers/staging/media/rkvdec/rkvdec.c
@@ -1027,12 +1027,6 @@  static int rkvdec_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	/*
-	 * Bump ACLK to max. possible freq. (500 MHz) to improve performance
-	 * When 4k video playback.
-	 */
-	clk_set_rate(rkvdec->clocks[0].clk, 500 * 1000 * 1000);
-
 	rkvdec->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(rkvdec->regs))
 		return PTR_ERR(rkvdec->regs);