6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hugo Villeneuve [ Upstream commit 64aa8b3a60a825134f7d866adf05c024bbe0c24c ] Since commit 56de5e305d4b ("clk: renesas: r9a07g044: Add MSTOP for RZ/G2L") we may get the following kernel panic, for some panels, when rebooting: systemd-shutdown[1]: Rebooting. Call trace: ... do_serror+0x28/0x68 el1h_64_error_handler+0x34/0x50 el1h_64_error+0x6c/0x70 rzg2l_mipi_dsi_host_transfer+0x114/0x458 (P) mipi_dsi_device_transfer+0x44/0x58 mipi_dsi_dcs_set_display_off_multi+0x9c/0xc4 ili9881c_unprepare+0x38/0x88 drm_panel_unprepare+0xbc/0x108 This happens for panels that need to send MIPI-DSI commands in their unprepare() callback. Since the MIPI-DSI interface is stopped at that point, rzg2l_mipi_dsi_host_transfer() triggers the kernel panic. Fix by moving rzg2l_mipi_dsi_stop() to new callback function rzg2l_mipi_dsi_atomic_post_disable(). With this change we now have the correct power-down/stop sequence: systemd-shutdown[1]: Rebooting. rzg2l-mipi-dsi 10850000.dsi: rzg2l_mipi_dsi_atomic_disable(): entry ili9881c-dsi 10850000.dsi.0: ili9881c_unprepare(): entry rzg2l-mipi-dsi 10850000.dsi: rzg2l_mipi_dsi_atomic_post_disable(): entry reboot: Restarting system Suggested-by: Biju Das Signed-off-by: Hugo Villeneuve Tested-by: Biju Das Link: https://patch.msgid.link/20260112154333.655352-1-hugo@hugovil.com Signed-off-by: Biju Das Signed-off-by: Sasha Levin --- drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c index a9216a99b2be1..5b8da2b6cbd0f 100644 --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c @@ -574,6 +574,13 @@ static void rzg2l_mipi_dsi_atomic_disable(struct drm_bridge *bridge, rzg2l_mipi_dsi_stop_video(dsi); rzg2l_mipi_dsi_stop_hs_clock(dsi); +} + +static void rzg2l_mipi_dsi_atomic_post_disable(struct drm_bridge *bridge, + struct drm_bridge_state *old_bridge_state) +{ + struct rzg2l_mipi_dsi *dsi = bridge_to_rzg2l_mipi_dsi(bridge); + rzg2l_mipi_dsi_stop(dsi); } @@ -598,6 +605,7 @@ static const struct drm_bridge_funcs rzg2l_mipi_dsi_bridge_ops = { .atomic_reset = drm_atomic_helper_bridge_reset, .atomic_enable = rzg2l_mipi_dsi_atomic_enable, .atomic_disable = rzg2l_mipi_dsi_atomic_disable, + .atomic_post_disable = rzg2l_mipi_dsi_atomic_post_disable, .mode_valid = rzg2l_mipi_dsi_bridge_mode_valid, }; -- 2.53.0