| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <7f520044-59d7-f369-1503-9065e6c0e42d@quicinc.com>
Date: Tue, 3 Oct 2023 15:54:25 -0700
From: Kuogee Hsieh <quic_khsieh@...cinc.com>
To: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
CC: <dri-devel@...ts.freedesktop.org>, <robdclark@...il.com>,
<sean@...rly.run>, <swboyd@...omium.org>, <dianders@...omium.org>,
<vkoul@...nel.org>, <daniel@...ll.ch>, <airlied@...il.com>,
<agross@...nel.org>, <andersson@...nel.org>,
<quic_abhinavk@...cinc.com>, <quic_jesszhan@...cinc.com>,
<quic_sbillaka@...cinc.com>, <marijn.suijten@...ainline.org>,
<freedreno@...ts.freedesktop.org>, <linux-arm-msm@...r.kernel.org>,
<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 7/8] drm/msm/dp: add
pm_runtime_force_suspend()/resume()
On 10/3/2023 3:36 PM, Dmitry Baryshkov wrote:
> On Wed, 4 Oct 2023 at 01:12, Kuogee Hsieh <quic_khsieh@...cinc.com> wrote:
>>
>> On 10/3/2023 10:53 AM, Dmitry Baryshkov wrote:
>>> On Tue, 3 Oct 2023 at 19:44, Kuogee Hsieh <quic_khsieh@...cinc.com> wrote:
>>>> On 9/27/2023 3:00 PM, Dmitry Baryshkov wrote:
>>>>> On Wed, 27 Sept 2023 at 23:54, Kuogee Hsieh <quic_khsieh@...cinc.com> wrote:
>>>>>> After incorporated pm_runtime framework into eDP/DP driver, the
>>>>> incorporating
>>>>>
>>>>>
>>>>>> original dp_pm_suspend() to handle power off both DP phy and
>>>>>> controller during suspend and dp_pm_resume() to handle power on
>>>>>> both DP phy and controller during resume are not necessary since
>>>>>> those function are replaced by dp_pm_runtime_suspend() and
>>>>>> dp_pm_runtime_resume() through pm runtime framework.
>>>>>> Therefore add pm framework provides functions,
>>>>>> pm_runtime_force_suspend()/resume() to complete incorporating pm
>>>>>> runtime framework into DP driver.
>>>>>>
>>>>>> Changes in v4:
>>>>>> -- drop both dp_pm_prepare() and dp_pm_compete() from this change
>>>>>> -- delete ST_SUSPENDED state
>>>>>> -- rewording commit text to add more details regrading the purpose
>>>>>> of this change
>>>>>>
>>>>>> Changes in v3:
>>>>>> -- replace dp_pm_suspend() with pm_runtime_force_suspend()
>>>>>> -- replace dp_pm_resume() with pm_runtime_force_resume()
>>>>>>
>>>>>> Signed-off-by: Kuogee Hsieh <quic_khsieh@...cinc.com>
>>>>>> ---
>>>>>> drivers/gpu/drm/msm/dp/dp_display.c | 113 ++----------------------------------
>>>>>> 1 file changed, 5 insertions(+), 108 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
>>>>>> index 9158a2c..711d262 100644
>>>>>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
>>>>>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
>>>>>> @@ -49,7 +49,6 @@ enum {
>>>>>> ST_CONNECTED,
>>>>>> ST_DISCONNECT_PENDING,
>>>>>> ST_DISPLAY_OFF,
>>>>>> - ST_SUSPENDED,
>>>>>> };
>>>>>>
>>>>>> enum {
>>>>>> @@ -560,7 +559,7 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
>>>>>> drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
>>>>>> dp->dp_display.connector_type, state);
>>>>>>
>>>>>> - if (state == ST_DISPLAY_OFF || state == ST_SUSPENDED) {
>>>>>> + if (state == ST_DISPLAY_OFF) {
>>>>>> mutex_unlock(&dp->event_mutex);
>>>>>> return 0;
>>>>>> }
>>>>>> @@ -674,7 +673,7 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
>>>>>> drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
>>>>>> dp->dp_display.connector_type, state);
>>>>>>
>>>>>> - if (state == ST_DISPLAY_OFF || state == ST_SUSPENDED) {
>>>>>> + if (state == ST_DISPLAY_OFF) {
>>>>>> mutex_unlock(&dp->event_mutex);
>>>>>> return 0;
>>>>>> }
>>>>>> @@ -1321,110 +1320,10 @@ static int dp_pm_runtime_resume(struct device *dev)
>>>>>> return 0;
>>>>>> }
>>>>>>
>>>>>> -static int dp_pm_resume(struct device *dev)
>>>>>> -{
>>>>>> - struct platform_device *pdev = to_platform_device(dev);
>>>>>> - struct msm_dp *dp_display = platform_get_drvdata(pdev);
>>>>>> - struct dp_display_private *dp;
>>>>>> - int sink_count = 0;
>>>>>> -
>>>>>> - dp = container_of(dp_display, struct dp_display_private, dp_display);
>>>>>> -
>>>>>> - mutex_lock(&dp->event_mutex);
>>>>>> -
>>>>>> - drm_dbg_dp(dp->drm_dev,
>>>>>> - "Before, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
>>>>>> - dp->dp_display.connector_type, dp->core_initialized,
>>>>>> - dp->phy_initialized, dp_display->power_on);
>>>>>> -
>>>>>> - /* start from disconnected state */
>>>>>> - dp->hpd_state = ST_DISCONNECTED;
>>>>>> -
>>>>>> - /* turn on dp ctrl/phy */
>>>>>> - dp_display_host_init(dp);
>>>>>> -
>>>>>> - if (dp_display->is_edp)
>>>>>> - dp_catalog_ctrl_hpd_enable(dp->catalog);
>>>>>> -
>>>>>> - if (dp_catalog_link_is_connected(dp->catalog)) {
>>>>>> - /*
>>>>>> - * set sink to normal operation mode -- D0
>>>>>> - * before dpcd read
>>>>>> - */
>>>>>> - dp_display_host_phy_init(dp);
>>>>>> - dp_link_psm_config(dp->link, &dp->panel->link_info, false);
>>>>>> - sink_count = drm_dp_read_sink_count(dp->aux);
>>>>>> - if (sink_count < 0)
>>>>>> - sink_count = 0;
>>>>>> -
>>>>>> - dp_display_host_phy_exit(dp);
>>>>>> - }
>>>>>> -
>>>>>> - dp->link->sink_count = sink_count;
>>>>>> - /*
>>>>>> - * can not declared display is connected unless
>>>>>> - * HDMI cable is plugged in and sink_count of
>>>>>> - * dongle become 1
>>>>>> - * also only signal audio when disconnected
>>>>>> - */
>>>>>> - if (dp->link->sink_count) {
>>>>>> - dp->dp_display.link_ready = true;
>>>>>> - } else {
>>>>>> - dp->dp_display.link_ready = false;
>>>>>> - dp_display_handle_plugged_change(dp_display, false);
>>>>>> - }
>>>>>> -
>>>>>> - drm_dbg_dp(dp->drm_dev,
>>>>>> - "After, type=%d sink=%d conn=%d core_init=%d phy_init=%d power=%d\n",
>>>>>> - dp->dp_display.connector_type, dp->link->sink_count,
>>>>>> - dp->dp_display.link_ready, dp->core_initialized,
>>>>>> - dp->phy_initialized, dp_display->power_on);
>>>>>> -
>>>>>> - mutex_unlock(&dp->event_mutex);
>>>>>> -
>>>>>> - return 0;
>>>>>> -}
>>>>>> -
>>>>>> -static int dp_pm_suspend(struct device *dev)
>>>>>> -{
>>>>>> - struct platform_device *pdev = to_platform_device(dev);
>>>>>> - struct msm_dp *dp_display = platform_get_drvdata(pdev);
>>>>>> - struct dp_display_private *dp;
>>>>>> -
>>>>>> - dp = container_of(dp_display, struct dp_display_private, dp_display);
>>>>>> -
>>>>>> - mutex_lock(&dp->event_mutex);
>>>>>> -
>>>>>> - drm_dbg_dp(dp->drm_dev,
>>>>>> - "Before, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
>>>>>> - dp->dp_display.connector_type, dp->core_initialized,
>>>>>> - dp->phy_initialized, dp_display->power_on);
>>>>>> -
>>>>>> - /* mainlink enabled */
>>>>>> - if (dp_power_clk_status(dp->power, DP_CTRL_PM))
>>>>>> - dp_ctrl_off_link_stream(dp->ctrl);
>>>>>> -
>>>>>> - dp_display_host_phy_exit(dp);
>>>>> I was under the impression that dp_pm_runtime_suspend / _resume
>>>>> functions perform phy init/exit only in eDP cases. Can we really drop
>>>>> the main suspend/resume functions?
>>>> yes on eDP case since it is embedded.
>>> Let me ask the same question in a different way:
>>>
>>> dp_pm_suspend() / dp_pm_resume() functions contain several calls to DP
>>> functions. Why can we drop them now? Maybe they had to be dropped in
>>> one of the previous patches, when you have added proper runtime PM
>>> support?
>>>
>>> Could you please confirm that after each patch the DP driver is
>>> working, that there are no hidden dependencies between patches?
>> patch #5 ==> drm/msm/dp: incorporate pm_runtime framework into DP driver
>>
>> patch #6 ==> drm/msm/dp: delete EV_HPD_INIT_SETUP
>>
>> patch #7 ==> drm/msm/dp: add pm_runtime_force_suspend()/resume() <==
>> both dp_pm_suspend() and dp_pm_resume() are dropped here
>>
>>
>> Patch #5 is this patch and dp_pm_suspend() and dp_pm_resume() still kept.
>>
>> patch #7 drop both dp_pm_suspend() and dp_pm_resume().
> This makes me wonder if squashing #5 and #7 would have resulted in a
> cleaner and easier to understand patch. This way we'd be able to
> observer code moved from suspend/resume to runtime_suspend /
> runtime_resume
ok, i will merge both two patches together
>> In order to keep every patch work for suspend/resume test, I drop
>> dp_pm_susend() and dp_pm_resuem() at patch #7.
>>
>> yes, i confirm each patch DP driver is working.
> Ack, thank you.
>
>>
>>>> for external DP case, there are two steps
>>>>
>>>> step 1: enable DP controller's hpd block and start waiting for hpd
>>>> interrupts at dp_display_hpd_enable()
>> The step number I mentioned here is for hpd_internal == true case.
>>> Step 1 should be optional. DP should be functional even if the
>>> .hpd_enable was not called. Have you tested this usecase?
>> yes, for hpd_internal == false, step #1 is not required.
>>
>> however I do not have device to test it.
> You have. Just add a dp-connector with hpd-gpios to any of your
> DP-enabled devices and change the pinctrl for hpd pin to use the gpio
> function instead of HPD.
>
>> But i think it should work since pm_runtime_resume_and_get() and
>> pm_runtime_put_sync() to dp_hpd_plug_handle() and dp_hpd_unplug_handle()
>> respectively.
> Ack.
>
>
>>>> step 2: at plugin interrupts, dp_display_host_phy_init()
>>>>
>>>> step 3: at unplug interrupt: dp_bridge_atomic_post_disable()
>>>> dp_display_host_phy_exi()
>>>>
>>>> at runtime, there is loop between step 2 and step 3
>>>>
>>>> step 4: disable DP controller's hpd block
>>>>
>>>>>> -
>>>>>> - /* host_init will be called at pm_resume */
>>>>>> - dp_display_host_deinit(dp);
>>>>>> -
>>>>>> - dp->hpd_state = ST_SUSPENDED;
>>>>>> -
>>>>>> - drm_dbg_dp(dp->drm_dev,
>>>>>> - "After, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
>>>>>> - dp->dp_display.connector_type, dp->core_initialized,
>>>>>> - dp->phy_initialized, dp_display->power_on);
>>>>>> -
>>>>>> - mutex_unlock(&dp->event_mutex);
>>>>>> -
>>>>>> - return 0;
>>>>>> -}
>>>>>> -
>>>>>> static const struct dev_pm_ops dp_pm_ops = {
>>>>>> SET_RUNTIME_PM_OPS(dp_pm_runtime_suspend, dp_pm_runtime_resume, NULL)
>>>>>> - .suspend = dp_pm_suspend,
>>>>>> - .resume = dp_pm_resume,
>>>>>> + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
>>>>>> + pm_runtime_force_resume)
>>>>>> };
>>>>>>
>>>>>> static struct platform_driver dp_display_driver = {
>>>>>> @@ -1658,9 +1557,6 @@ void dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
>>>>>>
>>>>>> dp_display = container_of(dp, struct dp_display_private, dp_display);
>>>>>>
>>>>>> - if (dp->is_edp)
>>>>>> - dp_hpd_unplug_handle(dp_display, 0);
>>>>> Why?
>>>> dp_hpd_unplug_handle() does not tear down phy.
>>>>
>>>> Therefore eDP does not need to call unplug handle.
>>> I don't fully understand your argument here. Could you please
>>> describe, why this function call was necessary beforehand and what is
>>> being changed now, so that it becomes unnecessary?
>> dp_hpd_unplug_handle() is not necessary for eDP from very beginning
>> since dp_bridge_atomic_enable() do it all (tear down link and phy).
> Excuse me? Where does dp_bridge_atomic_enable() tear down the link?
my bad, it is dp_bridge_atomic_post_disable()
>
>> I think it was added long time ago mistakenly just like to be
>> compatible with external DP since external DP always have
>> dp_hpd_unplug_handle() called from irq_handle().
>>
>> i can restore it back if you insist it.
> I insist on having clean documented patches. If function call was not
> necessary beforehand, please drop it in the separate patch with proper
> description of why and what.
> ok, will restore it back.
>>
>>>>
>>>>>> -
>>>>>> mutex_lock(&dp_display->event_mutex);
>>>>>>
>>>>>> state = dp_display->hpd_state;
>>>>>> @@ -1748,6 +1644,7 @@ void dp_bridge_hpd_disable(struct drm_bridge *bridge)
>>>>>> dp_catalog_ctrl_hpd_disable(dp->catalog);
>>>>>>
>>>>>> dp_display->internal_hpd = false;
>>>>>> + dp->hpd_state = ST_DISCONNECTED;
>>>>> Why? We have only disabled sending of the HPD events. The dongle might
>>>>> still be connected.
>>>> dp_bridge_hpd_disable() disable dp controller hpd block (no more hpd
>>>> interrupt will be received).
>>>>
>>>> dp_bridge_hpd_disable() should happen after DP main link had been teared
>>>> down already.
>>> No, this assumption is incorrect. hpd_disable can happen at any point
>>> during runtime.
>>> It merely disables HPD interrupt generation, it has nothing to do with
>>> the DP block being enabled or not.
>>>
>>>> Therefore hpd_state need to be in default state so that next plugin
>>>> handle will be start with correct state.
>>>>
>>>>
>>>>>> pm_runtime_mark_last_busy(&dp->pdev->dev);
>>>>>> pm_runtime_put_autosuspend(&dp->pdev->dev);
>>>>>> --
>>>>>> 2.7.4
>>>>>>
>>>>> --
>>>>> With best wishes
>>>>>
>>>>> Dmitry
>>>
>
>
Powered by blists - more mailing lists