Re: [PATCH v8 02/13] drm/bridge: cdns-dsi: Fix phy de-init and flag it so

Tomi Valkeinen
2025-02-04T13:24:25Z

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