On Sat, Oct 31, 2026 at 11:03:01PM +0800, Qianhui Xu wrote:
> The bonded-DSI command path kept a file-scoped `static bool
> dsi_bonded_cmd_failed` next to the global manager instance, so bonded
> state was split across two storage classes. Move the flag into
> struct msm_dsi_manager (msm_dsim_glb) so the manager owns all of it and
> nothing mutable stays file-scoped. READ_ONCE/WRITE_ONCE use is unchanged,
> so behaviour is identical.
>
> Signed-off-by: Qianhui Xu <[email protected]>
> ---
> drivers/gpu/drm/msm/dsi/dsi_manager.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> index 559c07a8b9..93d636220b 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> @@ -30,6 +30,7 @@ struct msm_dsi_manager {
> bool is_bonded_dsi;
> bool is_sync_needed;
> bool is_sm8750;
> + bool bonded_cmd_failed;
> int master_dsi_link_id;
> };
>
> @@ -37,8 +38,10 @@ static struct msm_dsi_manager msm_dsim_glb = {
> .master_dsi_link_id = -1,
> };
>
> +/* Serialises bonded command transactions; the failure flag it guards lives
> in
> + * msm_dsim_glb so no bonded state is file-scoped.
> + */
If all fields guarded by this lock are held in another place, then the
lock should also go. Nit: please check the recommended form for the
block comment.
> static DEFINE_MUTEX(dsi_bonded_cmd_lock);
Hmm what is your base kernel? I don't see these definitions.
> -static bool dsi_bonded_cmd_failed;
>
> #define IS_BONDED_DSI() (msm_dsim_glb.is_bonded_dsi)
> #define IS_SYNC_NEEDED() (msm_dsim_glb.is_sync_needed)
> @@ -51,7 +54,8 @@ static bool dsi_mgr_uses_bonded_cmd(void)
>
> bool msm_dsi_manager_cmd_failed(void)
> {
> - return dsi_mgr_uses_bonded_cmd() && READ_ONCE(dsi_bonded_cmd_failed);
> + return dsi_mgr_uses_bonded_cmd() &&
> + READ_ONCE(msm_dsim_glb.bonded_cmd_failed);
> }
>
> static inline struct msm_dsi *dsi_mgr_get_dsi(int id)
> @@ -374,7 +378,7 @@ static void dsi_mgr_bridge_enable(struct drm_bridge
> *bridge,
> if (!panel->prepared) {
> dev_err(&msm_dsi->pdev->dev,
> "panel is not prepared; refusing video enable\n");
> - WRITE_ONCE(dsi_bonded_cmd_failed, true);
> + WRITE_ONCE(msm_dsim_glb.bonded_cmd_failed, true);
> return;
> }
>
> @@ -646,7 +650,7 @@ static int dsi_mgr_bonded_cmd_xfer(const struct
> mipi_dsi_msg *msg)
> ret = master_ret < 0 ? master_ret : slave_ret < 0 ? slave_ret : len;
> if (ret < 0) {
> /* Never reuse a packet buffer while either DMA engine is
> unresolved. */
> - WRITE_ONCE(dsi_bonded_cmd_failed, true);
> + WRITE_ONCE(msm_dsim_glb.bonded_cmd_failed, true);
> dev_err(&master_dsi->pdev->dev,
> "bonded command DMA failed: master=%d peer=%d\n",
> master_ret, slave_ret);
> --
> 2.53.0
>
--
With best wishes
Dmitry
