[0/2] drm/meson: vclk: revert and re-fix vclk calculations

Message

Christian Hewitt Jan. 10, 2025, 7:44 a.m. UTC

Patch 1 reverts a previous fix for loss of HDMI sync when playing YUV420
@ 59.94 media. The patch does resolve a calculation issue. It also makes
all fractional rates invalid which is a bigger problem.

Patch 2 provides a proper fix after I figured out the actual root cause
of the original problem. This time the maths checks out.

Apologies to the stable team as the original patch has been applied to
a wide range of older and LTS kernels (as far as 5.10). Please let me
know if combining the two patches into a single 'fix the previous fix'
patch would be preferred?

Christian

Christian Hewitt (2):
  Revert "drm/meson: vclk: fix calculation of 59.94 fractional rates"
  drm/meson: vclk: fix precision in vclk calculations

 drivers/gpu/drm/meson/meson_encoder_hdmi.c | 42 +++++++++++-----------
 drivers/gpu/drm/meson/meson_vclk.c         |  7 ++--
 2 files changed, 25 insertions(+), 24 deletions(-)

Comments

Neil Armstrong Feb. 24, 2025, 8:39 a.m. UTC | #1

On 10/01/2025 08:44, Christian Hewitt wrote:
> Patch 1 reverts a previous fix for loss of HDMI sync when playing YUV420
> @ 59.94 media. The patch does resolve a calculation issue. It also makes
> all fractional rates invalid which is a bigger problem.
> 
> Patch 2 provides a proper fix after I figured out the actual root cause
> of the original problem. This time the maths checks out.
> 
> Apologies to the stable team as the original patch has been applied to
> a wide range of older and LTS kernels (as far as 5.10). Please let me
> know if combining the two patches into a single 'fix the previous fix'
> patch would be preferred?
> 
> Christian
> 
> Christian Hewitt (2):
>    Revert "drm/meson: vclk: fix calculation of 59.94 fractional rates"
>    drm/meson: vclk: fix precision in vclk calculations
> 
>   drivers/gpu/drm/meson/meson_encoder_hdmi.c | 42 +++++++++++-----------
>   drivers/gpu/drm/meson/meson_vclk.c         |  7 ++--
>   2 files changed, 25 insertions(+), 24 deletions(-)
> 

LGTM

Reviewed-by: Neil Armstrong <[e-mail]>