6.10-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Zimmermann tzimmermann@suse.de
commit 0ce91928ec62d189b5c51816e325f02587b53118 upstream.
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.
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 Reviewed-by: Jocelyn Falempe jfalempe@redhat.com Link: https://patchwork.freedesktop.org/patch/msgid/20240717143319.104012-2-tzimme... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(-)
--- 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 *de 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) { --- 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 *d 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); --- 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>
@@ -1641,11 +1642,35 @@ static int ast_astdp_connector_helper_de 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 = {