On 26/01/2025 21:15, Aradhya Bhatia wrote:

From: Aradhya Bhatia a-bhatia1@ti.com

The driver code doesn't have a Phy de-initialization path as yet, and so it does not clear the phy_initialized flag while suspending. This is a problem because after resume the driver looks at this flag to determine if a Phy re-initialization is required or not. It is in fact required because the hardware is resuming from a suspend, but the driver does not carry out any re-initialization causing the D-Phy to not work at all.

Call the counterparts of phy_init() and phy_power_on(), that are phy_exit() and phy_power_off(), from _bridge_post_disable(), and clear the flags so that the Phy can be initialized again when required.

Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework") Cc: Stable List stable@vger.kernel.org Signed-off-by: Aradhya Bhatia a-bhatia1@ti.com Signed-off-by: Aradhya Bhatia aradhya.bhatia@linux.dev

---

drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 2f897ea5e80a..b0a1a6774ea6 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -680,6 +680,11 @@ static void cdns_dsi_bridge_post_disable(struct drm_bridge *bridge) struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); struct cdns_dsi *dsi = input_to_dsi(input);

• dsi->phy_initialized = false;
• dsi->link_initialized = false;
• phy_power_off(dsi->dphy);
• phy_exit(dsi->dphy);
• pm_runtime_put(dsi->base.dev); }

@@ -1152,7 +1157,6 @@ static int __maybe_unused cdns_dsi_suspend(struct device *dev) clk_disable_unprepare(dsi->dsi_sys_clk); clk_disable_unprepare(dsi->dsi_p_clk); reset_control_assert(dsi->dsi_p_rst);

• dsi->link_initialized = false; return 0; }

Reviewed-by: Tomi Valkeinen tomi.valkeinen@ideasonboard.com

Tomi