rm68200_prepare() returns without disabling the supply regulator if
EXIT_SLEEP_MODE or SET_DISPLAY_ON fails. Since drm_panel_prepare() does
not mark the panel as prepared on failure, drm_panel_unprepare() does
not call the driver's unprepare() callback, leaving the regulator
enable count elevated even after subsequent successful
prepare/unprepare cycles.
On failure, restore the reset GPIO to its unprepared state, following
the existing reset sequence in unprepare(), and disable the supply
regulator before returning the original error.
Fixes: 2b7ed18bed1a ("drm/panel: Add support for Raydium RM68200 panel driver")
Reported-by: Sashiko <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]
Signed-off-by: Hsieh Hung-En <[email protected]>
---
Notes:
In this patch, rm68200_init_sequence() still returns void and only
logs DCS write failures. These failures do not cause prepare() to
return early. A later patch in this series will propagate
initialization errors through prepare(), where this cleanup path
will also handle them.
The error path does not send SET_DISPLAY_OFF or ENTER_SLEEP_MODE,
as DCS communication may already have failed. Instead, it follows
the existing reset and regulator shutdown sequence in unprepare().
drivers/gpu/drm/panel/panel-raydium-rm68200.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/panel/panel-raydium-rm68200.c
b/drivers/gpu/drm/panel/panel-raydium-rm68200.c
index c535dc931903..3a59eb00274d 100644
--- a/drivers/gpu/drm/panel/panel-raydium-rm68200.c
+++ b/drivers/gpu/drm/panel/panel-raydium-rm68200.c
@@ -277,17 +277,26 @@ static int rm68200_prepare(struct drm_panel *panel)
ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
if (ret)
- return ret;
+ goto assert_reset;
msleep(125);
ret = mipi_dsi_dcs_set_display_on(dsi);
if (ret)
- return ret;
+ goto assert_reset;
msleep(20);
return 0;
+
+assert_reset:
+ if (ctx->reset_gpio) {
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+ msleep(20);
+ }
+ /* Balance the regulator enable count on prepare failure. */
+ regulator_disable(ctx->supply);
+ return ret;
}
static int rm68200_get_modes(struct drm_panel *panel,
--
2.43.0
