Messages in this thread | | | Subject | Re: [PATCH] drm: clarify adjusted_mode documentation for bridges | From | Archit Taneja <> | Date | Thu, 19 Apr 2018 22:30:27 +0530 |
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On Thursday 19 April 2018 09:20 PM, Philippe CORNU wrote: > Hi Archit & Andrzej, > > May I ask you please a short review of this documentation update. > Many thanks > Philippe :-) > > On 04/09/2018 05:24 PM, Philippe Cornu wrote: >> This patch clarifies the adjusted_mode documentation >> for bridges. >>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
>> Signed-off-by: Philippe Cornu <philippe.cornu@st.com> >> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> >> --- >> This patch follows discussions in: >> - "drm: clarify adjusted_mode for a bridge connected to a crtc" >> https://patchwork.freedesktop.org/patch/206801/ >> - "drm: bridge: Constify mode arguments to bridge .mode_set() operation" >> https://patchwork.freedesktop.org/patch/215449/ >> >> include/drm/drm_bridge.h | 16 ++++++++++++++++ >> include/drm/drm_crtc.h | 11 +++++++---- >> 2 files changed, 23 insertions(+), 4 deletions(-) >> >> diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h >> index 3270fec46979..7d632c6a9214 100644 >> --- a/include/drm/drm_bridge.h >> +++ b/include/drm/drm_bridge.h >> @@ -178,6 +178,22 @@ struct drm_bridge_funcs { >> * then this would be &drm_encoder_helper_funcs.mode_set. The display >> * pipe (i.e. clocks and timing signals) is off when this function is >> * called. >> + * >> + * The adjusted_mode parameter corresponds to the mode output by the CRTC >> + * for the first bridge in the chain. It can be different from the mode >> + * parameter that contains the desired mode for the connector at the end >> + * of the bridges chain, for instance when the first bridge in the chain >> + * performs scaling. The adjusted mode is mostly useful for the first >> + * bridge in the chain and is likely irrelevant for the other bridges. >> + * >> + * For atomic drivers the adjusted_mode is the mode stored in >> + * &drm_crtc_state.adjusted_mode. >> + * >> + * NOTE: >> + * >> + * If a need arises to store and access modes adjusted for other locations >> + * than the connection between the CRTC and the first bridge, the DRM >> + * framework will have to be extended with DRM bridge states. >> */ >> void (*mode_set)(struct drm_bridge *bridge, >> struct drm_display_mode *mode, >> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h >> index a2d81d2907a9..65f749a9e9d3 100644 >> --- a/include/drm/drm_crtc.h >> +++ b/include/drm/drm_crtc.h >> @@ -134,10 +134,13 @@ struct drm_crtc_state { >> * >> * Internal display timings which can be used by the driver to handle >> * differences between the mode requested by userspace in @mode and what >> - * is actually programmed into the hardware. It is purely driver >> - * implementation defined what exactly this adjusted mode means. Usually >> - * it is used to store the hardware display timings used between the >> - * CRTC and encoder blocks. >> + * is actually programmed into the hardware. >> + * >> + * For drivers using drm_bridge, this stores the hardware display timings >> + * used between the CRTC and the first bridge. For other drivers, the >> + * meaning of the adjusted_mode field is purely driver implementation >> + * defined information, and will usually be used to store the hardware >> + * display timings used between the CRTC and encoder blocks. >> */ >> struct drm_display_mode adjusted_mode; >>
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