On Mon, Oct 28, 2024 at 01:36:58PM +0100, Marek Vasut wrote: > On 10/28/24 10:25 AM, Maxime Ripard wrote: > > On Sat, Oct 26, 2024 at 06:10:01AM +0200, Marek Vasut wrote: > > > Horizontal Timing Control0 Register 1/2 (HTIM01/HTIM02) Register > > > bitfields description state "These bits must be multiple of even > > > pixel". It is not possible to simply align every bitfield to the > > > nearest even pixel, because that would unalign the line width and > > > cause visible distortion. Instead, attempt to re-align the timings > > > such that the hardware requirement is fulfilled without changing > > > the line width if at all possible. > > > > > > Warn the user in case a panel with odd active pixel width or full > > > line width is used, this is not possible to support with this one > > > bridge. > > > > > > Signed-off-by: Marek Vasut <[email protected]> > > > --- > > > Cc: Andrzej Hajda <[email protected]> > > > Cc: David Airlie <[email protected]> > > > Cc: Jernej Skrabec <[email protected]> > > > Cc: Jonas Karlman <[email protected]> > > > Cc: Laurent Pinchart <[email protected]> > > > Cc: Maarten Lankhorst <[email protected]> > > > Cc: Maxime Ripard <[email protected]> > > > Cc: Neil Armstrong <[email protected]> > > > Cc: Robert Foss <[email protected]> > > > Cc: Simona Vetter <[email protected]> > > > Cc: Thomas Zimmermann <[email protected]> > > > Cc: [email protected] > > > --- > > > drivers/gpu/drm/bridge/tc358767.c | 63 +++++++++++++++++++++++++++++-- > > > 1 file changed, 60 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/bridge/tc358767.c > > > b/drivers/gpu/drm/bridge/tc358767.c > > > index 0a6894498267e..7968183510e63 100644 > > > --- a/drivers/gpu/drm/bridge/tc358767.c > > > +++ b/drivers/gpu/drm/bridge/tc358767.c > > > @@ -901,6 +901,63 @@ static int tc_set_common_video_mode(struct tc_data > > > *tc, > > > int vsync_len = mode->vsync_end - mode->vsync_start; > > > int ret; > > > + /* > > > + * Horizontal Timing Control0 Register 1/2 (HTIM01/HTIM02) Register > > > + * bitfields description state "These bits must be multiple of even > > > + * pixel". It is not possible to simply align every bitfield to the > > > + * nearest even pixel, because that would unalign the line width. > > > + * Instead, attempt to re-align the timings. > > > + */ > > > + > > > + /* Panels with odd active pixel count are not supported by the bridge */ > > > + if (mode->hdisplay & 1) > > > + dev_warn(tc->dev, "Panels with odd pixel count per active line > > > are not supported.\n"); > > > + > > > + /* HPW is odd */ > > > + if (hsync_len & 1) { > > > + /* Make sure there is some margin left */ > > > + if (left_margin >= 2) { > > > + /* Align HPW up */ > > > + hsync_len++; > > > + left_margin--; > > > + } else if (right_margin >= 2) { > > > + /* Align HPW up */ > > > + hsync_len++; > > > + right_margin--; > > > + } else if (hsync_len > 2) { > > > + /* Align HPW down as last-resort option */ > > > + hsync_len--; > > > + left_margin++; > > > + } else { > > > + dev_warn(tc->dev, "HPW is odd, not enough margins to > > > compensate.\n"); > > > + } > > > + } > > > + > > > + /* HBP is odd (HPW is surely even now) */ > > > + if (left_margin & 1) { > > > + /* Make sure there is some margin left */ > > > + if (right_margin >= 2) { > > > + /* Align HBP up */ > > > + left_margin++; > > > + right_margin--; > > > + } else if (hsync_len > 2) { > > > + /* HPW is surely even and > 2, which means at least 4 */ > > > + hsync_len -= 2; > > > + /* > > > + * Subtract 2 from sync pulse and distribute it between > > > + * margins. This aligns HBP and keeps HPW aligned. > > > + */ > > > + left_margin++; > > > + right_margin++; > > > + } else { > > > + dev_warn(tc->dev, "HBP is odd, not enough pixels to > > > compensate.\n"); > > > + } > > > + } > > > + > > > + /* HFP is odd (HBP and HPW is surely even now) */ > > > + if (right_margin & 1) > > > + dev_warn(tc->dev, "HFP is odd, panels with odd pixel count per > > > full line are not supported.\n"); > > > + > > > > This should all happen in atomic_check, and reject modes that can't > > be supported.
> No, that would reject panels I need to support and which can be > supported by this bridge. Then drop the warnings, either you support it or you don't. Maxime
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