diff options
Diffstat (limited to 'drivers/gpu/drm/msm/dp/dp_aux.c')
| -rw-r--r-- | drivers/gpu/drm/msm/dp/dp_aux.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c index 03f4951c4..e67a80d56 100644 --- a/drivers/gpu/drm/msm/dp/dp_aux.c +++ b/drivers/gpu/drm/msm/dp/dp_aux.c @@ -35,6 +35,7 @@ struct dp_aux_private { bool no_send_stop; bool initted; bool is_edp; + bool enable_xfers; u32 offset; u32 segment; @@ -302,6 +303,17 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux, } /* + * If we're using DP and an external display isn't connected then the + * transfer won't succeed. Return right away. If we don't do this we + * can end up with long timeouts if someone tries to access the DP AUX + * character device when no DP device is connected. + */ + if (!aux->is_edp && !aux->enable_xfers) { + ret = -ENXIO; + goto exit; + } + + /* * For eDP it's important to give a reasonably long wait here for HPD * to be asserted. This is because the panel driver may have _just_ * turned on the panel and then tried to do an AUX transfer. The panel @@ -433,6 +445,14 @@ irqreturn_t dp_aux_isr(struct drm_dp_aux *dp_aux) return IRQ_HANDLED; } +void dp_aux_enable_xfers(struct drm_dp_aux *dp_aux, bool enabled) +{ + struct dp_aux_private *aux; + + aux = container_of(dp_aux, struct dp_aux_private, dp_aux); + aux->enable_xfers = enabled; +} + void dp_aux_reconfig(struct drm_dp_aux *dp_aux) { struct dp_aux_private *aux; |