Messages in this thread | | | Subject | Re: [PATCH] drm/bridge: parade-ps8640: Link device to ensure suspend/resume order | From | AngeloGioacchino Del Regno <> | Date | Tue, 4 Jan 2022 15:48:08 +0100 |
| |
Il 04/01/22 15:22, Robert Foss ha scritto: > Hey AngeloGioacchino, > > On Tue, 2 Nov 2021 at 14:08, AngeloGioacchino Del Regno > <angelogioacchino.delregno@collabora.com> wrote: >> >> Entering suspend while the display attached to this bridge is still on >> makes the resume sequence to resume the bridge first, display last: >> when this happens, we get a timeout while resuming the bridge, as its >> MCU will get stuck due to the display being unpowered. >> >> On the other hand, on mt8173-elm, closing the lid makes the display to >> get powered off first, bridge last, so at resume time the sequence is >> swapped (compared to the first example) and everything just works >> as expected. >> >> Add a stateless device link to the DRM device that this bridge belongs >> to, ensuring a correct resume sequence and solving the unability to >> correctly resume bridge operation in the first mentioned example. >> >> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> >> --- >> drivers/gpu/drm/bridge/parade-ps8640.c | 22 ++++++++++++++++++++-- >> 1 file changed, 20 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c >> index 45100edd745b..191cc196c9d1 100644 >> --- a/drivers/gpu/drm/bridge/parade-ps8640.c >> +++ b/drivers/gpu/drm/bridge/parade-ps8640.c >> @@ -100,6 +100,7 @@ struct ps8640 { >> struct regulator_bulk_data supplies[2]; >> struct gpio_desc *gpio_reset; >> struct gpio_desc *gpio_powerdown; >> + struct device_link *link; >> bool powered; >> }; >> >> @@ -460,10 +461,23 @@ static int ps8640_bridge_attach(struct drm_bridge *bridge, >> goto err_aux_register; >> } >> >> + ps_bridge->link = device_link_add(bridge->dev->dev, dev, DL_FLAG_STATELESS); >> + if (!ps_bridge->link) { >> + dev_err(dev, "failed to create device link"); >> + ret = -EINVAL; >> + goto err_devlink; >> + } >> + >> /* Attach the panel-bridge to the dsi bridge */ >> - return drm_bridge_attach(bridge->encoder, ps_bridge->panel_bridge, >> + ret = drm_bridge_attach(bridge->encoder, ps_bridge->panel_bridge, >> &ps_bridge->bridge, flags); >> + if (ret) >> + goto err_bridge_attach; >> >> +err_bridge_attach: >> + device_link_del(ps_bridge->link); >> +err_devlink: >> + drm_dp_aux_unregister(&ps_bridge->aux); >> err_aux_register: >> mipi_dsi_detach(dsi); >> err_dsi_attach: >> @@ -473,7 +487,11 @@ static int ps8640_bridge_attach(struct drm_bridge *bridge, >> >> static void ps8640_bridge_detach(struct drm_bridge *bridge) >> { >> - drm_dp_aux_unregister(&bridge_to_ps8640(bridge)->aux); >> + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge); >> + >> + drm_dp_aux_unregister(&ps_bridge->aux); >> + if (ps_bridge->link) >> + device_link_del(ps_bridge->link); >> } >> >> static struct edid *ps8640_bridge_get_edid(struct drm_bridge *bridge, >> -- >> 2.33.1 >> > > This patch does not apply on drm-misc-next, could you rebase it on the > current branch? >
Sure, I'll rebase it asap.
| |