RE: [PATCH 1/2] usb: dwc3: core: don't trigger runtime pm when remove driver

From: Jun Li <jun.li@nxp.com>
To: Jun Li <jun.li@nxp.com>, "balbi@kernel.org" <balbi@kernel.org>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	dl-linux-imx <linux-imx@nxp.com>
Subject: RE: [PATCH 1/2] usb: dwc3: core: don't trigger runtime pm when remove driver
Date: Fri, 21 Aug 2020 01:47:26 +0000	[thread overview]
Message-ID: <VE1PR04MB6528011CB06E23D32636DECF895B0@VE1PR04MB6528.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <1595940161-3700-1-git-send-email-jun.li@nxp.com>

Hi

> -----Original Message-----
> From: Jun Li <jun.li@nxp.com>
> Sent: Tuesday, July 28, 2020 8:47 PM
> To: balbi@kernel.org
> Cc: gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; dl-linux-imx
> <linux-imx@nxp.com>
> Subject: [PATCH 1/2] usb: dwc3: core: don't trigger runtime pm when remove driver
> 
> No need to trigger runtime pm in driver removal, otherwise if user disable auto
> suspend via sys file, runtime suspend may be entered, which will call dwc3_core_exit()
> again and there will be clock disable not balance warning:
> 
> [ 2026.820154] xhci-hcd xhci-hcd.0.auto: remove, state 4 [ 2026.825268] usb usb2:
> USB disconnect, device number 1 [ 2026.831017] xhci-hcd xhci-hcd.0.auto: USB bus
> 2 deregistered [ 2026.836806] xhci-hcd xhci-hcd.0.auto: remove, state 4
> [ 2026.842029] usb usb1: USB disconnect, device number 1 [ 2026.848029] xhci-hcd
> xhci-hcd.0.auto: USB bus 1 deregistered [ 2026.865889] ------------[ cut
> here ]------------ [ 2026.870506] usb2_ctrl_root_clk already disabled [ 2026.875082]
> WARNING: CPU: 0 PID: 731 at drivers/clk/clk.c:958
> clk_core_disable+0xa0/0xa8
> [ 2026.883170] Modules linked in: dwc3(-) phy_fsl_imx8mq_usb [last
> unloaded: dwc3]
> [ 2026.890488] CPU: 0 PID: 731 Comm: rmmod Not tainted
> 5.8.0-rc7-00280-g9d08cca-dirty #245 [ 2026.898489] Hardware name: NXP i.MX8MQ EVK
> (DT) [ 2026.903020] pstate: 20000085 (nzCv daIf -PAN -UAO BTYPE=--) [ 2026.908594]
> pc : clk_core_disable+0xa0/0xa8 [ 2026.912777] lr : clk_core_disable+0xa0/0xa8
> [ 2026.916958] sp : ffff8000121b39a0 [ 2026.920271] x29: ffff8000121b39a0 x28:
> ffff0000b11f3700 [ 2026.925583] x27: 0000000000000000 x26: ffff0000b539c700
> [ 2026.930895] x25: 000001d7e44e1232 x24: ffff0000b76fa800 [ 2026.936208] x23:
> ffff0000b76fa6f8 x22: ffff800008d01040 [ 2026.941520] x21: ffff0000b539ce00 x20:
> ffff0000b7105000 [ 2026.946832] x19: ffff0000b7105000 x18: 0000000000000010
> [ 2026.952144] x17: 0000000000000001 x16: 0000000000000000 [ 2026.957456] x15:
> ffff0000b11f3b70 x14: ffffffffffffffff [ 2026.962768] x13: ffff8000921b36f7 x12:
> ffff8000121b36ff [ 2026.968080] x11: ffff8000119e1000 x10: ffff800011bf26d0
> [ 2026.973392] x9 : 0000000000000000 x8 : ffff800011bf3000 [ 2026.978704] x7 :
> ffff800010695d68 x6 : 0000000000000252 [ 2026.984016] x5 : ffff0000bb9881f0 x4 :
> 0000000000000000 [ 2026.989327] x3 : 0000000000000027 x2 : 0000000000000023
> [ 2026.994639] x1 : ac2fa471aa7cab00 x0 : 0000000000000000 [ 2026.999951] Call trace:
> [ 2027.002401]  clk_core_disable+0xa0/0xa8 [ 2027.006238]
> clk_core_disable_lock+0x20/0x38 [ 2027.010508]  clk_disable+0x1c/0x28
> [ 2027.013911]  clk_bulk_disable+0x34/0x50 [ 2027.017758]
> dwc3_core_exit+0xec/0x110 [dwc3] [ 2027.022122]  dwc3_suspend_common+0x84/0x188
> [dwc3] [ 2027.026919]  dwc3_runtime_suspend+0x74/0x9c [dwc3] [ 2027.031712]
> pm_generic_runtime_suspend+0x28/0x40
> [ 2027.036419]  genpd_runtime_suspend+0xa0/0x258 [ 2027.040777]
> __rpm_callback+0x88/0x140 [ 2027.044526]  rpm_callback+0x20/0x80 [ 2027.048015]
> rpm_suspend+0xd0/0x418 [ 2027.051503]  __pm_runtime_suspend+0x58/0xa0
> [ 2027.055693]  dwc3_runtime_idle+0x7c/0x90 [dwc3] [ 2027.060224]
> __rpm_callback+0x88/0x140 [ 2027.063973]  rpm_idle+0x78/0x150 [ 2027.067201]
> __pm_runtime_idle+0x58/0xa0 [ 2027.071130]  dwc3_remove+0x64/0xc0 [dwc3]
> [ 2027.075140]  platform_drv_remove+0x28/0x48 [ 2027.079239]
> device_release_driver_internal+0xf4/0x1c0
> [ 2027.084377]  driver_detach+0x4c/0xd8
> [ 2027.087954]  bus_remove_driver+0x54/0xa8 [ 2027.091877]
> driver_unregister+0x2c/0x58 [ 2027.095799]  platform_driver_unregister+0x10/0x18
> [ 2027.100509]  dwc3_driver_exit+0x14/0x1408 [dwc3] [ 2027.105129]
> __arm64_sys_delete_module+0x178/0x218
> [ 2027.109922]  el0_svc_common.constprop.0+0x68/0x160
> [ 2027.114714]  do_el0_svc+0x20/0x80
> [ 2027.118031]  el0_sync_handler+0x88/0x190 [ 2027.121953]  el0_sync+0x140/0x180
> [ 2027.125267] ---[ end trace 027f4f8189958f1f ]--- [ 2027.129976] ------------[ cut
> here ]------------
> 
> Fixes: fc8bb91bc83e ("usb: dwc3: implement runtime PM")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Li Jun <jun.li@nxp.com>
> ---
>  drivers/usb/dwc3/core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index
> 5c52da5..0444018 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1590,9 +1590,9 @@ static int dwc3_remove(struct platform_device *pdev)
>  	dwc3_core_exit(dwc);
>  	dwc3_ulpi_exit(dwc);
> 
> -	pm_runtime_put_sync(&pdev->dev);
> -	pm_runtime_allow(&pdev->dev);
>  	pm_runtime_disable(&pdev->dev);
> +	pm_runtime_put_noidle(&pdev->dev);
> +	pm_runtime_set_suspended(&pdev->dev);
> 
>  	dwc3_free_event_buffers(dwc);
>  	dwc3_free_scratch_buffers(dwc);
> --
> 2.7.4

A gentle ping...

Li Jun