On 17/07/2024 16:24, Thomas Zimmermann wrote:

Power up the ASTDP connector for connection status detection if the connector is not active. Keep it powered if a display is attached.

This fixes a bug where the connector does not come back after disconnecting the display. The encoder's atomic_disable turns off power on the physical connector. Further HPD reads will fail, thus preventing the driver from detecting re-connected displays.

For connectors that are actively used, only test the HPD flag without touching power.

Thanks, it looks good to me.

Reviewed-by: Jocelyn Falempe jfalempe@redhat.com

Fixes: f81bb0ac7872 ("drm/ast: report connection status on Display Port.") Cc: Jocelyn Falempe jfalempe@redhat.com Cc: Thomas Zimmermann tzimmermann@suse.de Cc: Dave Airlie airlied@redhat.com Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # v6.6+ Signed-off-by: Thomas Zimmermann tzimmermann@suse.de

---

drivers/gpu/drm/ast/ast_dp.c | 7 +++++++ drivers/gpu/drm/ast/ast_drv.h | 1 + drivers/gpu/drm/ast/ast_mode.c | 29 +++++++++++++++++++++++++++-- 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ast/ast_dp.c b/drivers/gpu/drm/ast/ast_dp.c index 1e9259416980..e6c7f0d64e99 100644 --- a/drivers/gpu/drm/ast/ast_dp.c +++ b/drivers/gpu/drm/ast/ast_dp.c @@ -158,7 +158,14 @@ void ast_dp_launch(struct drm_device *dev) ASTDP_HOST_EDID_READ_DONE); } +bool ast_dp_power_is_on(struct ast_device *ast) +{

• u8 vgacre3;
• vgacre3 = ast_get_index_reg(ast, AST_IO_VGACRI, 0xe3);

• return !(vgacre3 & AST_DP_PHY_SLEEP);

+} void ast_dp_power_on_off(struct drm_device *dev, bool on) { diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h index ba3d86973995..47bab5596c16 100644 --- a/drivers/gpu/drm/ast/ast_drv.h +++ b/drivers/gpu/drm/ast/ast_drv.h @@ -472,6 +472,7 @@ void ast_init_3rdtx(struct drm_device *dev); bool ast_astdp_is_connected(struct ast_device *ast); int ast_astdp_read_edid(struct drm_device *dev, u8 *ediddata); void ast_dp_launch(struct drm_device *dev); +bool ast_dp_power_is_on(struct ast_device *ast); void ast_dp_power_on_off(struct drm_device *dev, bool no); void ast_dp_set_on_off(struct drm_device *dev, bool no); void ast_dp_set_mode(struct drm_crtc *crtc, struct ast_vbios_mode_info *vbios_mode); diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index dc8f639e82fd..049ee1477c33 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -28,6 +28,7 @@

• Authors: Dave Airlie airlied@redhat.com

*/ +#include <linux/delay.h> #include <linux/export.h> #include <linux/pci.h> @@ -1687,11 +1688,35 @@ static int ast_astdp_connector_helper_detect_ctx(struct drm_connector *connector struct drm_modeset_acquire_ctx *ctx, bool force) {

• struct drm_device *dev = connector->dev; struct ast_device *ast = to_ast_device(connector->dev);
• enum drm_connector_status status = connector_status_disconnected;
• struct drm_connector_state *connector_state = connector->state;
• bool is_active = false;
• mutex_lock(&ast->modeset_lock);
• if (connector_state && connector_state->crtc) {

• struct drm_crtc_state *crtc_state = connector_state->crtc->state;
  

• if (crtc_state && crtc_state->active)
  

• 	is_active = true;
  

• }
• if (!is_active && !ast_dp_power_is_on(ast)) {

• ast_dp_power_on_off(dev, true);
  

• msleep(50);
  

• }

if (ast_astdp_is_connected(ast))

• return connector_status_connected;
  

• return connector_status_disconnected;

• status = connector_status_connected;
  

• if (!is_active && status == connector_status_disconnected)

• ast_dp_power_on_off(dev, false);
  

• mutex_unlock(&ast->modeset_lock);
• return status; }

static const struct drm_connector_helper_funcs ast_astdp_connector_helper_funcs = {