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drm/mcde: dsi: Enable clocks in pre_enable() instead of mode_set()

The DSI initialization sequence incorrectly assumes that the mode_set()
function of the DRM bridge is always called when (re-)enabling the display.
This is not necessarily the case.

Keeping the device idle in the framebuffer console for a while results
in the display being turned off using the disable() function. However,
as soon as any key is pressed only (pre_)enable() are called.
mode_set() is skipped because the mode has not been changed.

In this case, the DSI HS/LP clocks are never turned back on,
preventing the display from working.

Fix this by moving a part of the initialization sequence from
mode_set() to pre_enable(). Keep most of the video mode setup in
mode_set() since most of the registers are only dependent on the mode
that is set for the panel - there is no need to write them again each
time we re-enable the display.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191106165835.2863-7-stephan@gerhold.net
This commit is contained in:
Stephan Gerhold 2019-11-06 17:58:34 +01:00 committed by Linus Walleij
parent 1f79c60e10
commit 3c5824bdc4

View File

@ -562,21 +562,6 @@ static void mcde_dsi_setup_video_mode(struct mcde_dsi *d,
DSI_VID_VCA_SETTING2_EXACT_BURST_LIMIT_SHIFT;
writel(val, d->regs + DSI_VID_VCA_SETTING2);
/* Put IF1 into video mode */
val = readl(d->regs + DSI_MCTL_MAIN_DATA_CTL);
val |= DSI_MCTL_MAIN_DATA_CTL_IF1_MODE;
writel(val, d->regs + DSI_MCTL_MAIN_DATA_CTL);
/* Disable command mode on IF1 */
val = readl(d->regs + DSI_CMD_MODE_CTL);
val &= ~DSI_CMD_MODE_CTL_IF1_LP_EN;
writel(val, d->regs + DSI_CMD_MODE_CTL);
/* Enable some error interrupts */
val = readl(d->regs + DSI_VID_MODE_STS_CTL);
val |= DSI_VID_MODE_STS_CTL_ERR_MISSING_VSYNC;
val |= DSI_VID_MODE_STS_CTL_ERR_MISSING_DATA;
writel(val, d->regs + DSI_VID_MODE_STS_CTL);
}
static void mcde_dsi_start(struct mcde_dsi *d)
@ -700,26 +685,13 @@ static void mcde_dsi_bridge_enable(struct drm_bridge *bridge)
dev_info(d->dev, "enable DSI master\n");
};
static void mcde_dsi_bridge_mode_set(struct drm_bridge *bridge,
const struct drm_display_mode *mode,
const struct drm_display_mode *adj)
static void mcde_dsi_bridge_pre_enable(struct drm_bridge *bridge)
{
struct mcde_dsi *d = bridge_to_mcde_dsi(bridge);
unsigned long pixel_clock_hz = mode->clock * 1000;
unsigned long hs_freq, lp_freq;
u32 val;
int ret;
if (!d->mdsi) {
dev_err(d->dev, "no DSI device attached to encoder!\n");
return;
}
dev_info(d->dev, "set DSI master to %dx%d %lu Hz %s mode\n",
mode->hdisplay, mode->vdisplay, pixel_clock_hz,
(d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO) ? "VIDEO" : "CMD"
);
/* Copy maximum clock frequencies */
if (d->mdsi->lp_rate)
lp_freq = d->mdsi->lp_rate;
@ -758,7 +730,21 @@ static void mcde_dsi_bridge_mode_set(struct drm_bridge *bridge,
d->hs_freq);
if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
mcde_dsi_setup_video_mode(d, mode);
/* Put IF1 into video mode */
val = readl(d->regs + DSI_MCTL_MAIN_DATA_CTL);
val |= DSI_MCTL_MAIN_DATA_CTL_IF1_MODE;
writel(val, d->regs + DSI_MCTL_MAIN_DATA_CTL);
/* Disable command mode on IF1 */
val = readl(d->regs + DSI_CMD_MODE_CTL);
val &= ~DSI_CMD_MODE_CTL_IF1_LP_EN;
writel(val, d->regs + DSI_CMD_MODE_CTL);
/* Enable some error interrupts */
val = readl(d->regs + DSI_VID_MODE_STS_CTL);
val |= DSI_VID_MODE_STS_CTL_ERR_MISSING_VSYNC;
val |= DSI_VID_MODE_STS_CTL_ERR_MISSING_DATA;
writel(val, d->regs + DSI_VID_MODE_STS_CTL);
} else {
/* Command mode, clear IF1 ID */
val = readl(d->regs + DSI_CMD_MODE_CTL);
@ -772,6 +758,26 @@ static void mcde_dsi_bridge_mode_set(struct drm_bridge *bridge,
}
}
static void mcde_dsi_bridge_mode_set(struct drm_bridge *bridge,
const struct drm_display_mode *mode,
const struct drm_display_mode *adj)
{
struct mcde_dsi *d = bridge_to_mcde_dsi(bridge);
if (!d->mdsi) {
dev_err(d->dev, "no DSI device attached to encoder!\n");
return;
}
dev_info(d->dev, "set DSI master to %dx%d %u Hz %s mode\n",
mode->hdisplay, mode->vdisplay, mode->clock * 1000,
(d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO) ? "VIDEO" : "CMD"
);
if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO)
mcde_dsi_setup_video_mode(d, mode);
}
static void mcde_dsi_wait_for_command_mode_stop(struct mcde_dsi *d)
{
u32 val;
@ -863,6 +869,7 @@ static const struct drm_bridge_funcs mcde_dsi_bridge_funcs = {
.mode_set = mcde_dsi_bridge_mode_set,
.disable = mcde_dsi_bridge_disable,
.enable = mcde_dsi_bridge_enable,
.pre_enable = mcde_dsi_bridge_pre_enable,
};
static int mcde_dsi_bind(struct device *dev, struct device *master,