Messages in this thread | | | Date | Wed, 24 May 2023 10:29:57 +0800 | Subject | Re: [PATCH] drm/ast: Fix modeset failed on DisplayPort | From | Jammy Huang <> |
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Hi Thomas,
Do you have other suggestion for this patch??
Please kindly advise.
On 2023/4/25 下午 03:39, Jammy Huang wrote: > 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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