Re: [PATCH v2] usb: dwc3: core: Fix gadget for system suspend/resume

[Roger Quadros <rogerq@ti.com>]

Hi Felipe,

Looks like we missed this one. Could you please pick this up for -rc?
Thanks.

cheers,
-roger

On 03/26/2014 11:43 AM, Roger Quadros wrote:
> During system resume, if the event buffers are not setup before
> the gadget controller starts then we start with invalid context
> and this can lead to bus access errors. This is especially true for
> platforms that loose the controller context during system suspend.
> e.g. AM437x.
> 
> The following backtrace was found when the system is suspended
> and resumed with g_zero loaded on AM437x-evm (USB cable connected
> to host all the while).
> 
> [  120.981506] WARNING: CPU: 0 PID: 1656 at drivers/bus/omap_l3_noc.c:137 l3_interrupt_handler+0x198/0x28c()
> [  120.981514] L3 custom error: MASTER:USB0 WR TARGET:GPMC
> [  120.981638] Modules linked in: g_mass_storage usb_f_mass_storage libcomposite configfs bufferclass_ti(O) omaplfb(O) cryptodev(O) dwc3 snd_soc_evm snd_soc_omap snd_pe
> [  120.981659] CPU: 0 PID: 1656 Comm: sh Tainted: G           O 3.12.10-gc559824 #1
> [  120.981669] Backtrace:
> [  120.981705] [<c0017880>] (dump_backtrace+0x0/0x10c) from [<c0017a1c>] (show_stack+0x18/0x1c)
> [  120.981730]  r6:c02819ac r5:00000009 r4:ec137cb8 r3:00000000
> [  120.981767] [<c0017a04>] (show_stack+0x0/0x1c) from [<c056c0b0>] (dump_stack+0x20/0x28)
> [  120.981802] [<c056c090>] (dump_stack+0x0/0x28) from [<c0046d08>] (warn_slowpath_common+0x70/0x90)
> [  120.981830] [<c0046c98>] (warn_slowpath_common+0x0/0x90) from [<c0046dcc>] (warn_slowpath_fmt+0x38/0x40)
> [  120.981856]  r8:c0855eb0 r7:00000002 r6:f1000700 r5:00000007 r4:80080003
> [  120.981886] [<c0046d94>] (warn_slowpath_fmt+0x0/0x40) from [<c02819ac>] (l3_interrupt_handler+0x198/0x28c)
> [  120.981900]  r3:c0801ab8 r2:c06cb354
> [  120.981936] [<c0281814>] (l3_interrupt_handler+0x0/0x28c) from [<c007162c>] (handle_irq_event_percpu+0x54/0x1b8)
> [  120.981962] [<c00715d8>] (handle_irq_event_percpu+0x0/0x1b8) from [<c00717c0>] (handle_irq_event+0x30/0x40)
> [  120.981993] [<c0071790>] (handle_irq_event+0x0/0x40) from [<c0074058>] (handle_fasteoi_irq+0x74/0x128)
> [  120.982006]  r4:ed0056c0 r3:00000000
> [  120.982033] [<c0073fe4>] (handle_fasteoi_irq+0x0/0x128) from [<c0070f34>] (generic_handle_irq+0x28/0x38)
> [  120.982046]  r4:0000002a r3:c0073fe4
> [  120.982085] [<c0070f0c>] (generic_handle_irq+0x0/0x38) from [<c0015560>] (handle_IRQ+0x38/0x8c)
> [  120.982098]  r4:c080137c r3:00000182
> [  120.982124] [<c0015528>] (handle_IRQ+0x0/0x8c) from [<c00087e0>] (gic_handle_irq+0x30/0x5c)
> [  120.982145]  r6:ec137dd0 r5:c07ac480 r4:fa24010c r3:00000100
> [  120.982169] [<c00087b0>] (gic_handle_irq+0x0/0x5c) from [<c056fcc0>] (__irq_svc+0x40/0x54)
> [  120.982179] Exception stack(0xec137dd0 to 0xec137e18)
> [  120.982195] 7dc0:                                     00000000 a00001d3 00000000 00000004
> [  120.982216] 7de0: a0000153 ec1d9010 c080de90 ec137e30 c080debc 00000000 ed756e44 ec137e2c
> [  120.982232] 7e00: ec137de0 ec137e18 bf1150e4 bf115474 60000153 ffffffff
> [  120.982253]  r7:ec137e04 r6:ffffffff r5:60000153 r4:bf115474
> [  120.982327] [<bf115438>] (dwc3_complete+0x0/0x40 [dwc3]) from [<c0338f50>] (dpm_complete+0xd4/0x19c)
> [  120.982341]  r5:ed756e10 r4:ed756e64
> [  120.982370] [<c0338e7c>] (dpm_complete+0x0/0x19c) from [<c0339034>] (dpm_resume_end+0x1c/0x20)
> [  120.982400] [<c0339018>] (dpm_resume_end+0x0/0x20) from [<c006d4ec>] (suspend_devices_and_enter+0x118/0x33c)
> [  120.982412]  r4:c0833da4 r3:00000000
> [  120.982436] [<c006d3d4>] (suspend_devices_and_enter+0x0/0x33c) from [<c006d928>] (pm_suspend+0x218/0x254)
> [  120.982458] [<c006d710>] (pm_suspend+0x0/0x254) from [<c006c594>] (state_store+0x70/0xc0)
> [  120.982478]  r6:c057a6cc r5:c06a8320 r4:00000003 r3:0000006d
> [  120.982515] [<c006c524>] (state_store+0x0/0xc0) from [<c0264cc0>] (kobj_attr_store+0x1c/0x28)
> [  120.982546] [<c0264ca4>] (kobj_attr_store+0x0/0x28) from [<c012ccb8>] (sysfs_write_file+0x170/0x1a4)
> [  120.982583] [<c012cb48>] (sysfs_write_file+0x0/0x1a4) from [<c00d17e4>] (vfs_write+0xb8/0x190)
> [  120.982611] [<c00d172c>] (vfs_write+0x0/0x190) from [<c00d1bf8>] (SyS_write+0x44/0x78)
> [  120.982641] [<c00d1bb4>] (SyS_write+0x0/0x78) from [<c0014660>] (ret_fast_syscall+0x0/0x30)
> 
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> Acked-by: Felipe Balbi <balbi@ti.com>
> ---
>  drivers/usb/dwc3/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index d001417..10aaaae 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -821,6 +821,7 @@ static void dwc3_complete(struct device *dev)
>  
>  	spin_lock_irqsave(&dwc->lock, flags);
>  
> +	dwc3_event_buffers_setup(dwc);
>  	switch (dwc->dr_mode) {
>  	case USB_DR_MODE_PERIPHERAL:
>  	case USB_DR_MODE_OTG:
> @@ -828,7 +829,6 @@ static void dwc3_complete(struct device *dev)
>  		/* FALLTHROUGH */
>  	case USB_DR_MODE_HOST:
>  	default:
> -		dwc3_event_buffers_setup(dwc);
>  		break;
>  	}
>  
>