| Message ID | 20220405204426.259074-13-nicolas.dufresne@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3,01/24] media: doc: Document dual use of H.264 pic_num/frame_num | expand |
On 05/04/2022 22:44, 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 frames -> frame Regards, Hans > this hack was simply compensating for their code being less > efficient. In my opinion, this hack should not have been included > upstream. > > Fixes: cd33c830448ba ("media: rkvdec: Add the rkvdec driver") > Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com> > Reviewed-by: Sebastian Fricke <sebastian.fricke@collabora.com> > Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> > --- > 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);
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);
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. Fixes: cd33c830448ba ("media: rkvdec: Add the rkvdec driver") Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com> Reviewed-by: Sebastian Fricke <sebastian.fricke@collabora.com> Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> --- drivers/staging/media/rkvdec/rkvdec.c | 6 ------ 1 file changed, 6 deletions(-)