diff options
| author | Eric Anholt <eric@anholt.net> | 2017-09-20 15:59:34 -0700 |
|---|---|---|
| committer | Eric Anholt <eric@anholt.net> | 2017-11-09 10:10:09 -0800 |
| commit | 32e823c63e90f7535ea1cc5311d25c0233e1456d (patch) | |
| tree | bcc1c6551bdff04d060975a2ecfe3f7ff0f0cb9e /drivers/gpu/drm/vc4/vc4_hdmi.c | |
| parent | 2e2b96ef7a9b71e1bf08439e363c18cf700bafec (diff) | |
drm/vc4: Reject HDMI modes with too high of clocks.
Peter Robinson reported issues on Fedora with 4k monitors not having
their modes filtered down to 1920x1080 on Raspberry Pi.
v2: Fix vc5 typo in place of vc4.
Cc: Peter Robinson <pbrobinson@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20170920225935.14566-1-eric@anholt.net
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v1)
Diffstat (limited to 'drivers/gpu/drm/vc4/vc4_hdmi.c')
| -rw-r--r-- | drivers/gpu/drm/vc4/vc4_hdmi.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 9a9a6b4acccf..ab3bcbe0bb93 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -693,7 +693,22 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder) } } +static enum drm_mode_status +vc4_hdmi_encoder_mode_valid(struct drm_encoder *crtc, + const struct drm_display_mode *mode) +{ + /* HSM clock must be 108% of the pixel clock. Additionally, + * the AXI clock needs to be at least 25% of pixel clock, but + * HSM ends up being the limiting factor. + */ + if (mode->clock > HSM_CLOCK_FREQ / (1000 * 108 / 100)) + return MODE_CLOCK_HIGH; + + return MODE_OK; +} + static const struct drm_encoder_helper_funcs vc4_hdmi_encoder_helper_funcs = { + .mode_valid = vc4_hdmi_encoder_mode_valid, .disable = vc4_hdmi_encoder_disable, .enable = vc4_hdmi_encoder_enable, }; |