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Tue, 3 Oct 2023 22:12:22 GMT Received: from [10.110.36.217] (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.36; Tue, 3 Oct 2023 15:12:20 -0700 Message-ID: <65740ce1-9645-cbae-3d5e-503c5f2ee4e8@quicinc.com> Date: Tue, 3 Oct 2023 15:12:20 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH v4 7/8] drm/msm/dp: add pm_runtime_force_suspend()/resume() Content-Language: en-US To: Dmitry Baryshkov CC: , , , , , , , , , , , , , , , , References: <1695848028-18023-1-git-send-email-quic_khsieh@quicinc.com> <1695848028-18023-8-git-send-email-quic_khsieh@quicinc.com> From: Kuogee Hsieh In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: 2NLNyzYrx42MRlbwtfbxKdZ9Ob51TYce X-Proofpoint-ORIG-GUID: 2NLNyzYrx42MRlbwtfbxKdZ9Ob51TYce X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.980,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-10-03_18,2023-10-02_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 mlxscore=0 mlxlogscore=999 bulkscore=0 impostorscore=0 adultscore=0 clxscore=1015 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2310030167 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/3/2023 10:53 AM, Dmitry Baryshkov wrote: > On Tue, 3 Oct 2023 at 19:44, Kuogee Hsieh wrote: >> >> On 9/27/2023 3:00 PM, Dmitry Baryshkov wrote: >>> On Wed, 27 Sept 2023 at 23:54, Kuogee Hsieh 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 >>>> --- >>>> 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(). 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. > >> 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. 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. >> 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). 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. >> >> >>>> - >>>> 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 > >