Messages in this thread | | | Date | Tue, 10 Oct 2023 15:28:54 +0800 | Subject | Re: [PATCH v2] usb: dwc3: core: Avoid resume dwc3 if already suspended in pm resume | From | wuliangfeng <> |
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Hi Thinh,
Sorry for my late reply because the national day holiday.
在 2023/10/3 2:18, Thinh Nguyen 写道: > On Fri, Sep 15, 2023, wuliangfeng wrote: >> Hi Thinh, >> >> On 2023/9/12 8:08, Thinh Nguyen wrote: >>> Hi, >>> >>> On Mon, Sep 11, 2023, William Wu wrote: >>>> If we enable PM runtime auto suspend for dwc3 on rockchip >>>> platforms (e.g. RK3562), it allows the dwc3 controller to >>>> enter runtime suspend if usb cable detached and power off >>>> the power domain of the controller. When system resume, if >>>> the dwc3 already in runtime suspended, it Shouldn't access >>>> the dwc3 registers in dwc3_resume() because its power domain >>>> maybe power off. >>>> >>>> Test on RK3562 tablet, this patch can help to avoid kernel >>>> panic when accessing the dwc3 registers in dwc3_resume() if >>>> the dwc3 is in runtime suspended and it's power domain is >>>> power off. >>> The controller should be woken up before this step. Can you provide more >>> detail on what led to this? >> Yes, the power domain of the usb controller will be enabled by the framework >> of the pm generic domain before dwc3 resume if the system enter suspend and >> exit suspend normally. However, in my test case,if the system fail to enter >> suspend because of some devices's problem, and then goto recovery process, >> the power domain of the usb controller will not be enable before dwc3 >> resume. > Ok. > >>> e.g. some questions: >>> Who handles the waking up of the controller? Is it the phy driver? Is >>> the phy driver not detecting a resume? Or did the resume fail? Does this >>> occur consistently? >>> >>> Thanks, >>> Thinh >> This issue occurs occasionally on RK3562 EVB with Type-C USB, and enable >> autosuspend for dwc3 controller. >> >> Here is the test steps: >> >> 1. Power on the RK3562 EVB and the Type-C USB interface is in unconnected >> state. >> >> 2. Makesure the dwc3 controller enter runtime suspend, and its power domain >> is disabled. >> >> 3. Do system suspend/resume stress test. >> >> 4. The issue occurs occasionally with the following log: >> >> [ 251.681091][ T4331] PM: suspend entry (deep) >> [ 251.778975][ T4331] Filesystems sync: 0.097 seconds >> [ 251.779025][ T4331] Freezing user space processes ... (elapsed 0.005 >> seconds) done. >> [ 251.784819][ T4331] OOM killer disabled. >> [ 251.784851][ T4331] Freezing remaining freezable tasks ... (elapsed 0.004 >> seconds) done. >> [ 251.792719][ T503] [SKWIFI DBG] skw_suspend: WoW: enabled, skw flags: >> 0x302 >> [ 251.803701][ T4331] PM: dpm_run_callback(): >> platform_pm_suspend.cfi_jt+0x0/0x8 returns -16 >> [ 251.803779][ T75] PM: PM: Pending Wakeup Sources: alarmtimer.0.auto >> [ 251.803789][ T4331] PM: Device alarmtimer.0.a >> [ 251.803928][ T4331] PM: Some devices failed to suspend, or early wake >> event detected >> [ 251.804141][ T75] [SKWIFI DBG] skw_resume: skw flags: 0x300 >> [ 251.804715][ C2] SError Interrupt on CPU2, code 0xbf000000 -- SError >> [ 251.804725][ C2] CPU: 2 PID: 4331 Comm: binder:251_4 Tainted: G >> WC E 5.10.157-android13-4-00006-g73f337804fbc-ab9881769 #1 >> [ 251.804732][ C2] Hardware name: Rockchip RK3562 RK817 TABLET LP4 Board >> (DT) >> [ 251.804738][ C2] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO BTYPE=--) >> [ 251.804743][ C2] pc : el1_abort+0x40/0x68 >> [ 251.804748][ C2] lr : el1_abort+0x28/0x68 >> >> ...... >> >> [ 251.804965][ C2] Kernel panic - not syncing: Asynchronous SError >> Interrupt >> [ 251.804974][ C2] CPU: 2 PID: 4331 Comm: binder:251_4 Tainted: G >> WC E 5.10.157-android13-4-00006-g73f337804fbc-ab9881769 #1 >> [ 251.804980][ C2] Hardware name: Rockchip RK3562 RK817 TABLET LP4 Board >> (DT) >> [ 251.804984][ C2] Call trace: >> [ 251.804990][ C2] dump_backtrace.cfi_jt+0x0/0x8 >> [ 251.804995][ C2] dump_stack_lvl+0xc0/0x13c >> [ 251.805000][ C2] panic+0x174/0x468 >> [ 251.805006][ C2] arm64_serror_panic+0x1b0/0x200 >> [ 251.805010][ C2] do_serror+0x184/0x1e4 >> [ 251.805016][ C2] el1_error+0x94/0x118 >> [ 251.805020][ C2] el1_abort+0x40/0x68 >> [ 251.805026][ C2] el1_sync_handler+0x58/0x88 >> [ 251.805031][ C2] el1_sync+0x8c/0x140 >> [ 251.805035][ C2] dwc3_readl+0x30/0x1a0 >> [ 251.805040][ C2] dwc3_phy_setup+0x38/0x510 >> [ 251.805045][ C2] dwc3_core_init+0x68/0xcd4 >> [ 251.805051][ C2] dwc3_core_init_for_resume+0x10c/0x25c >> [ 251.805056][ C2] dwc3_resume_common+0x44/0x3d0 >> [ 251.805061][ C2] dwc3_resume+0x5c/0xb8 >> [ 251.805067][ C2] dpm_run_callback+0x70/0x488 >> [ 251.805071][ C2] device_resume+0x250/0x2f8 >> [ 251.805077][ C2] dpm_resume+0x258/0x9dc >> [ 251.805082][ C2] suspend_devices_and_enter+0x850/0xcac >> >> In this case, during suspend process, because the device alarmtimer failed >> to suspend, it break the system suspend in the funciton >> suspend_devices_and_enter(), and goto platform_recover() directly without >> enable the power domain of the controller, then trigger the Kernel panic in >> dwc3_resume(). >> > Thanks for the details. > >> For a comparison, in the normal case, if the system enter suspend normally, >> and after the system wakeup, the power domain of the controller will be >> enable by the framework of the pm generic domain before dwc3 resume. >> >> The function call stack like this: >> >> suspend_devices_and_enter --> >> >> suspend_enter --> >> >> dpm_resume_noirq --> dpm_noirq_resume_devices --> >> device_resume_noirq --> genpd_resume_noirq --> rockchip_pd_power (enable >> the power domain of the controller) >> >> dpm_resume_end --> >> >> dpm_resume --> device_resume --> dpm_run_callback --> dwc3_resume >> (access the controller safely) >> >> dpm_complete --> genpd_complete --> genpd_queue_power_off_work >> >> suspend_finish --> suspend_thaw_processes --> genpd_power_off_work_fn --> >> (diable the power domain of the controller to maintain the original runtime >> suspend state) >> > At what step do we restore the power domain when this happen? Looks like > there's a missing step in the suspend failure recovery to recover the > power domain. What we're doing here seems more like a workaround to > that, which unfortunately makes the code logic looks unclear IMO.
When then suspend successful, the power framework call dpm_resume_noirq() to enable on the power domain and then call dpm_complete() -> genpd_power_off_work_fn() to restore the original power domain state.
When the suspend failure happens,it seems that nobody recover the power domain in the power framework and rockchip platform pm_domains driver.
> > Can this be fixed in the lower layer?
For the time being, I haven't found a solution in the lower layer to fix this issue. I have to disable the dwc3 runtime feature on RK3562 GKI project.
> > Thanks, > Thinh
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