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| author | Linus Walleij <linus.walleij@linaro.org> | 2020-07-29 11:09:15 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2020-08-13 16:36:47 +0200 |
| commit | 709c27730a11d6681297d733eb8ee18166e9c38a (patch) | |
| tree | 3b148b6883c7524ce08aadb5ec505ccabb278f9b /drivers/gpu/drm/mcde/mcde_dsi.c | |
| parent | drm/mcde: Rename flow function (diff) | |
| download | linux-709c27730a11d6681297d733eb8ee18166e9c38a.tar.xz linux-709c27730a11d6681297d733eb8ee18166e9c38a.zip | |
drm/mcde: Fix display data flow control
Revamp the way that the flow of data to the display is
defined.
I realized that the hardware supports something like
5 different modes of flow: oneshot, command with TE IRQ,
command with BTA (bus turn around) and TE IRQ, video
with TE IRQ and video without TE IRQ instead synchronizing
to the output of the MCDE DSI formatter.
Like before the selection of the type of flow is done
from the DSI driver when we attach it to the MCDE and we
get to know what the display wants.
The new video mode synchronization method from the MCDE DSI
formatter is used on some upstream devices such as Golden.
This is the new default for video mode: stateless panels
do not as a rule generate TE IRQs.
Another semantic change is that we stop sending
a TE request before every command when sending data to
a display in command mode: this should only be explicitly
requested when using BTA, according to the vendor driver.
This has been tested and works fine with the command mode
displays I have. (All that are supported upstream.)
Reported-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Cc: Stephan Gerhold <stephan@gerhold.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20200729090915.252730-2-linus.walleij@linaro.org
Diffstat (limited to 'drivers/gpu/drm/mcde/mcde_dsi.c')
| -rw-r--r-- | drivers/gpu/drm/mcde/mcde_dsi.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/gpu/drm/mcde/mcde_dsi.c b/drivers/gpu/drm/mcde/mcde_dsi.c index 981923caa7e6..a342e898298b 100644 --- a/drivers/gpu/drm/mcde/mcde_dsi.c +++ b/drivers/gpu/drm/mcde/mcde_dsi.c @@ -148,9 +148,22 @@ static void mcde_dsi_attach_to_mcde(struct mcde_dsi *d) { d->mcde->mdsi = d->mdsi; - d->mcde->video_mode = !!(d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO); - /* Enable use of the TE signal for all command mode panels */ - d->mcde->te_sync = !d->mcde->video_mode; + /* + * Select the way the DSI data flow is pushing to the display: + * currently we just support video or command mode depending + * on the type of display. Video mode defaults to using the + * formatter itself for synchronization (stateless video panel). + * + * FIXME: add flags to struct mipi_dsi_device .flags to indicate + * displays that require BTA (bus turn around) so we can handle + * such displays as well. Figure out how to properly handle + * single frame on-demand updates with DRM for command mode + * displays (MCDE_COMMAND_ONESHOT_FLOW). + */ + if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO) + d->mcde->flow_mode = MCDE_VIDEO_FORMATTER_FLOW; + else + d->mcde->flow_mode = MCDE_COMMAND_TE_FLOW; } static int mcde_dsi_host_attach(struct mipi_dsi_host *host, |