Messages in this thread | | | Date | Tue, 25 Apr 2023 15:39:06 +0800 | Subject | Re: [PATCH] drm/ast: Fix modeset failed on DisplayPort | From | Jammy Huang <> |
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Hi Thomas,
I think DP501 is OK. It doesn't use ioregs in ast_dp501_read_edid().
On 2023/4/25 下午 03:27, Thomas Zimmermann wrote: > Hi > > Am 25.04.23 um 09:03 schrieb Jammy Huang: >> If we switch display and update cursor together, it could lead to >> modeset failed because of concurrent access to IO registers. >> >> Add lock protection in DP's edid access to avoid this problem. > > Thanks for the patch. I thought I fixed this issue already, but that > apparently only happened for SIL164 and VGA. > > What about ast_dp501_connector_helper_get_modes()? Does it require the > locking as well? > >> >> Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com> >> --- >> drivers/gpu/drm/ast/ast_mode.c | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/drivers/gpu/drm/ast/ast_mode.c >> b/drivers/gpu/drm/ast/ast_mode.c >> index 984ec590a7e7..fe5f1fd61361 100644 >> --- a/drivers/gpu/drm/ast/ast_mode.c >> +++ b/drivers/gpu/drm/ast/ast_mode.c >> @@ -1635,6 +1635,8 @@ static int ast_dp501_output_init(struct >> ast_private *ast) >> static int ast_astdp_connector_helper_get_modes(struct >> drm_connector *connector) >> { >> void *edid; >> + struct drm_device *dev = connector->dev; >> + struct ast_private *ast = to_ast_private(dev); > > We've meanwhile renamed ast_private to ast_device. Could you please > provide an updated patch for the drm-misc-next tree? > > Best regards > Thomas > >> int succ; >> int count; >> @@ -1643,10 +1645,18 @@ static int >> ast_astdp_connector_helper_get_modes(struct drm_connector *connector) >> if (!edid) >> goto err_drm_connector_update_edid_property; >> + /* >> + * Protect access to I/O registers from concurrent modesetting >> + * by acquiring the I/O-register lock. >> + */ >> + mutex_lock(&ast->ioregs_lock); >> + >> succ = ast_astdp_read_edid(connector->dev, edid); >> if (succ < 0) >> goto err_kfree; >> + mutex_unlock(&ast->ioregs_lock); >> + >> drm_connector_update_edid_property(connector, edid); >> count = drm_add_edid_modes(connector, edid); >> kfree(edid); >> @@ -1654,6 +1664,7 @@ static int >> ast_astdp_connector_helper_get_modes(struct drm_connector *connector) >> return count; >> err_kfree: >> + mutex_unlock(&ast->ioregs_lock); >> kfree(edid); >> err_drm_connector_update_edid_property: >> drm_connector_update_edid_property(connector, NULL); >> >> base-commit: 61d325dcbc05d8fef88110d35ef7776f3ac3f68b > -- Best Regards Jammy
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