usb: dwc3: gadget: Fix broken gadget on system suspend/resume

Message ID 1415804296-28980-1-git-send-email-rogerq@ti.com
State New
Headers show

Commit Message

Roger Quadros Nov. 12, 2014, 2:58 p.m.
On TI SoCs (e.g. DRA7) we don't support the DWC3 hibernation feature.
We need to stop the gadget controller while system suspend
else it results in L3 Bus errors on resume with broken
USB gadget on J6-evm.

[   55.718226] WARNING: CPU: 0 PID: 0 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x224/0x31c()
[   55.718232] 44000000.ocp:L3 Custom Error: MASTER USB3 TARGET GPMC (Idle): Data Access in User mode during Functional access
[   55.718263] Modules linked in: usb_f_ss_lb g_zero libcomposite configfs xhci_hcd btwilink bluetooth dwc3 6lowpan_iphc m25p80 dwc3_omap omap_remoteproc
[   55.718271] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.19-02011-g3ece3ca-dirty #658
[   55.718290] [<c0016090>] (unwind_backtrace) from [<c0012060>] (show_stack+0x10/0x14)
[   55.718302] [<c0012060>] (show_stack) from [<c062a2e4>] (dump_stack+0x78/0x94)
[   55.718315] [<c062a2e4>] (dump_stack) from [<c0043bc4>] (warn_slowpath_common+0x6c/0x90)
[   55.718325] [<c0043bc4>] (warn_slowpath_common) from [<c0043c7c>] (warn_slowpath_fmt+0x30/0x40)
[   55.718336] [<c0043c7c>] (warn_slowpath_fmt) from [<c030fb24>] (l3_interrupt_handler+0x224/0x31c)
[   55.718348] [<c030fb24>] (l3_interrupt_handler) from [<c0093010>] (handle_irq_event_percpu+0x5c/0x23c)
[   55.718358] [<c0093010>] (handle_irq_event_percpu) from [<c009322c>] (handle_irq_event+0x3c/0x5c)
[   55.718367] [<c009322c>] (handle_irq_event) from [<c0096160>] (handle_fasteoi_irq+0x98/0x158)
[   55.718377] [<c0096160>] (handle_fasteoi_irq) from [<c00929dc>] (generic_handle_irq+0x20/0x30)
[   55.718385] [<c00929dc>] (generic_handle_irq) from [<c000eea8>] (handle_IRQ+0x4c/0xb0)
[   55.718393] [<c000eea8>] (handle_IRQ) from [<c0008638>] (gic_handle_irq+0x28/0x5c)
[   55.718402] [<c0008638>] (gic_handle_irq) from [<c0630964>] (__irq_svc+0x44/0x5c)
[   55.718406] Exception stack(0xc09c1f68 to 0xc09c1fb0)
[   55.718412] 1f60:                   00000001 00000001 00000000 00000000 c09c0000 00000000
[   55.718418] 1f80: c09c0000 c09c0000 c0a7a1e4 c09c8938 c09c89b4 00000000 60000093 c09c1fb0
[   55.718423] 1fa0: c008a2e4 c00926cc 60000013 ffffffff
[   55.718433] [<c0630964>] (__irq_svc) from [<c00926cc>] (cpu_startup_entry+0x100/0x1f4)
[   55.718444] [<c00926cc>] (cpu_startup_entry) from [<c0901ac4>] (start_kernel+0x324/0x388)

Signed-off-by: Roger Quadros <rogerq@ti.com>
---
 drivers/usb/dwc3/gadget.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Felipe Balbi Nov. 12, 2014, 3:08 p.m. | #1
On Wed, Nov 12, 2014 at 04:58:16PM +0200, Roger Quadros wrote:
> On TI SoCs (e.g. DRA7) we don't support the DWC3 hibernation feature.
> We need to stop the gadget controller while system suspend
> else it results in L3 Bus errors on resume with broken
> USB gadget on J6-evm.
> 
> [   55.718226] WARNING: CPU: 0 PID: 0 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x224/0x31c()
> [   55.718232] 44000000.ocp:L3 Custom Error: MASTER USB3 TARGET GPMC (Idle): Data Access in User mode during Functional access
> [   55.718263] Modules linked in: usb_f_ss_lb g_zero libcomposite configfs xhci_hcd btwilink bluetooth dwc3 6lowpan_iphc m25p80 dwc3_omap omap_remoteproc
> [   55.718271] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.19-02011-g3ece3ca-dirty #658
> [   55.718290] [<c0016090>] (unwind_backtrace) from [<c0012060>] (show_stack+0x10/0x14)
> [   55.718302] [<c0012060>] (show_stack) from [<c062a2e4>] (dump_stack+0x78/0x94)
> [   55.718315] [<c062a2e4>] (dump_stack) from [<c0043bc4>] (warn_slowpath_common+0x6c/0x90)
> [   55.718325] [<c0043bc4>] (warn_slowpath_common) from [<c0043c7c>] (warn_slowpath_fmt+0x30/0x40)
> [   55.718336] [<c0043c7c>] (warn_slowpath_fmt) from [<c030fb24>] (l3_interrupt_handler+0x224/0x31c)
> [   55.718348] [<c030fb24>] (l3_interrupt_handler) from [<c0093010>] (handle_irq_event_percpu+0x5c/0x23c)
> [   55.718358] [<c0093010>] (handle_irq_event_percpu) from [<c009322c>] (handle_irq_event+0x3c/0x5c)
> [   55.718367] [<c009322c>] (handle_irq_event) from [<c0096160>] (handle_fasteoi_irq+0x98/0x158)
> [   55.718377] [<c0096160>] (handle_fasteoi_irq) from [<c00929dc>] (generic_handle_irq+0x20/0x30)
> [   55.718385] [<c00929dc>] (generic_handle_irq) from [<c000eea8>] (handle_IRQ+0x4c/0xb0)
> [   55.718393] [<c000eea8>] (handle_IRQ) from [<c0008638>] (gic_handle_irq+0x28/0x5c)
> [   55.718402] [<c0008638>] (gic_handle_irq) from [<c0630964>] (__irq_svc+0x44/0x5c)
> [   55.718406] Exception stack(0xc09c1f68 to 0xc09c1fb0)
> [   55.718412] 1f60:                   00000001 00000001 00000000 00000000 c09c0000 00000000
> [   55.718418] 1f80: c09c0000 c09c0000 c0a7a1e4 c09c8938 c09c89b4 00000000 60000093 c09c1fb0
> [   55.718423] 1fa0: c008a2e4 c00926cc 60000013 ffffffff
> [   55.718433] [<c0630964>] (__irq_svc) from [<c00926cc>] (cpu_startup_entry+0x100/0x1f4)
> [   55.718444] [<c00926cc>] (cpu_startup_entry) from [<c0901ac4>] (start_kernel+0x324/0x388)
> 
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> ---
>  drivers/usb/dwc3/gadget.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 3818b26..bc15b54 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2741,7 +2741,13 @@ int dwc3_gadget_prepare(struct dwc3 *dwc)

there is no more dwc3_gadget_prepare(), please rebase on 'next'.

>  {
>  	if (dwc->pullups_connected) {
>  		dwc3_gadget_disable_irq(dwc);
> -		dwc3_gadget_run_stop(dwc, true, true);
> +		if (dwc->has_hibernation) {
> +			dwc3_gadget_run_stop(dwc, true, true);
> +		} else {
> +			dwc3_gadget_run_stop(dwc, false, true);
> +			/* remember to connect back on resume */
> +			dwc->pullups_connected = true;
> +		}

Another thing you probably want to do is make sure there is nothing
pending on our request list because if there is, then we need to wait
for any in-flight transfers to complete before disconnecting.

I also wonder if current code isn't really fragile... I mean, when you
clear run_stop bit, you should notify the gadget by means of
->disconnect() and so on... But since we can't test this with mainline,
then it's difficult to tell.
Roger Quadros Nov. 12, 2014, 3:32 p.m. | #2
On 11/12/2014 05:08 PM, Felipe Balbi wrote:
> On Wed, Nov 12, 2014 at 04:58:16PM +0200, Roger Quadros wrote:
>> On TI SoCs (e.g. DRA7) we don't support the DWC3 hibernation feature.
>> We need to stop the gadget controller while system suspend
>> else it results in L3 Bus errors on resume with broken
>> USB gadget on J6-evm.
>>
>> [   55.718226] WARNING: CPU: 0 PID: 0 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x224/0x31c()
>> [   55.718232] 44000000.ocp:L3 Custom Error: MASTER USB3 TARGET GPMC (Idle): Data Access in User mode during Functional access
>> [   55.718263] Modules linked in: usb_f_ss_lb g_zero libcomposite configfs xhci_hcd btwilink bluetooth dwc3 6lowpan_iphc m25p80 dwc3_omap omap_remoteproc
>> [   55.718271] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.19-02011-g3ece3ca-dirty #658
>> [   55.718290] [<c0016090>] (unwind_backtrace) from [<c0012060>] (show_stack+0x10/0x14)
>> [   55.718302] [<c0012060>] (show_stack) from [<c062a2e4>] (dump_stack+0x78/0x94)
>> [   55.718315] [<c062a2e4>] (dump_stack) from [<c0043bc4>] (warn_slowpath_common+0x6c/0x90)
>> [   55.718325] [<c0043bc4>] (warn_slowpath_common) from [<c0043c7c>] (warn_slowpath_fmt+0x30/0x40)
>> [   55.718336] [<c0043c7c>] (warn_slowpath_fmt) from [<c030fb24>] (l3_interrupt_handler+0x224/0x31c)
>> [   55.718348] [<c030fb24>] (l3_interrupt_handler) from [<c0093010>] (handle_irq_event_percpu+0x5c/0x23c)
>> [   55.718358] [<c0093010>] (handle_irq_event_percpu) from [<c009322c>] (handle_irq_event+0x3c/0x5c)
>> [   55.718367] [<c009322c>] (handle_irq_event) from [<c0096160>] (handle_fasteoi_irq+0x98/0x158)
>> [   55.718377] [<c0096160>] (handle_fasteoi_irq) from [<c00929dc>] (generic_handle_irq+0x20/0x30)
>> [   55.718385] [<c00929dc>] (generic_handle_irq) from [<c000eea8>] (handle_IRQ+0x4c/0xb0)
>> [   55.718393] [<c000eea8>] (handle_IRQ) from [<c0008638>] (gic_handle_irq+0x28/0x5c)
>> [   55.718402] [<c0008638>] (gic_handle_irq) from [<c0630964>] (__irq_svc+0x44/0x5c)
>> [   55.718406] Exception stack(0xc09c1f68 to 0xc09c1fb0)
>> [   55.718412] 1f60:                   00000001 00000001 00000000 00000000 c09c0000 00000000
>> [   55.718418] 1f80: c09c0000 c09c0000 c0a7a1e4 c09c8938 c09c89b4 00000000 60000093 c09c1fb0
>> [   55.718423] 1fa0: c008a2e4 c00926cc 60000013 ffffffff
>> [   55.718433] [<c0630964>] (__irq_svc) from [<c00926cc>] (cpu_startup_entry+0x100/0x1f4)
>> [   55.718444] [<c00926cc>] (cpu_startup_entry) from [<c0901ac4>] (start_kernel+0x324/0x388)
>>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> ---
>>  drivers/usb/dwc3/gadget.c | 8 +++++++-
>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 3818b26..bc15b54 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -2741,7 +2741,13 @@ int dwc3_gadget_prepare(struct dwc3 *dwc)
> 
> there is no more dwc3_gadget_prepare(), please rebase on 'next'.

right.

> 
>>  {
>>  	if (dwc->pullups_connected) {
>>  		dwc3_gadget_disable_irq(dwc);
>> -		dwc3_gadget_run_stop(dwc, true, true);
>> +		if (dwc->has_hibernation) {
>> +			dwc3_gadget_run_stop(dwc, true, true);
>> +		} else {
>> +			dwc3_gadget_run_stop(dwc, false, true);
>> +			/* remember to connect back on resume */
>> +			dwc->pullups_connected = true;
>> +		}
> 
> Another thing you probably want to do is make sure there is nothing
> pending on our request list because if there is, then we need to wait
> for any in-flight transfers to complete before disconnecting.

shouldn't that check be done in dwc3_gadget_run_stop()?

> 
> I also wonder if current code isn't really fragile... I mean, when you
> clear run_stop bit, you should notify the gadget by means of
> ->disconnect() and so on... But since we can't test this with mainline,
> then it's difficult to tell.
> 
that is true.

cheers,
-roger
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Felipe Balbi Nov. 12, 2014, 3:36 p.m. | #3
Hi,

On Wed, Nov 12, 2014 at 05:32:00PM +0200, Roger Quadros wrote:
> On 11/12/2014 05:08 PM, Felipe Balbi wrote:
> > On Wed, Nov 12, 2014 at 04:58:16PM +0200, Roger Quadros wrote:
> >> On TI SoCs (e.g. DRA7) we don't support the DWC3 hibernation feature.
> >> We need to stop the gadget controller while system suspend
> >> else it results in L3 Bus errors on resume with broken
> >> USB gadget on J6-evm.
> >>
> >> [   55.718226] WARNING: CPU: 0 PID: 0 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x224/0x31c()
> >> [   55.718232] 44000000.ocp:L3 Custom Error: MASTER USB3 TARGET GPMC (Idle): Data Access in User mode during Functional access
> >> [   55.718263] Modules linked in: usb_f_ss_lb g_zero libcomposite configfs xhci_hcd btwilink bluetooth dwc3 6lowpan_iphc m25p80 dwc3_omap omap_remoteproc
> >> [   55.718271] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.19-02011-g3ece3ca-dirty #658
> >> [   55.718290] [<c0016090>] (unwind_backtrace) from [<c0012060>] (show_stack+0x10/0x14)
> >> [   55.718302] [<c0012060>] (show_stack) from [<c062a2e4>] (dump_stack+0x78/0x94)
> >> [   55.718315] [<c062a2e4>] (dump_stack) from [<c0043bc4>] (warn_slowpath_common+0x6c/0x90)
> >> [   55.718325] [<c0043bc4>] (warn_slowpath_common) from [<c0043c7c>] (warn_slowpath_fmt+0x30/0x40)
> >> [   55.718336] [<c0043c7c>] (warn_slowpath_fmt) from [<c030fb24>] (l3_interrupt_handler+0x224/0x31c)
> >> [   55.718348] [<c030fb24>] (l3_interrupt_handler) from [<c0093010>] (handle_irq_event_percpu+0x5c/0x23c)
> >> [   55.718358] [<c0093010>] (handle_irq_event_percpu) from [<c009322c>] (handle_irq_event+0x3c/0x5c)
> >> [   55.718367] [<c009322c>] (handle_irq_event) from [<c0096160>] (handle_fasteoi_irq+0x98/0x158)
> >> [   55.718377] [<c0096160>] (handle_fasteoi_irq) from [<c00929dc>] (generic_handle_irq+0x20/0x30)
> >> [   55.718385] [<c00929dc>] (generic_handle_irq) from [<c000eea8>] (handle_IRQ+0x4c/0xb0)
> >> [   55.718393] [<c000eea8>] (handle_IRQ) from [<c0008638>] (gic_handle_irq+0x28/0x5c)
> >> [   55.718402] [<c0008638>] (gic_handle_irq) from [<c0630964>] (__irq_svc+0x44/0x5c)
> >> [   55.718406] Exception stack(0xc09c1f68 to 0xc09c1fb0)
> >> [   55.718412] 1f60:                   00000001 00000001 00000000 00000000 c09c0000 00000000
> >> [   55.718418] 1f80: c09c0000 c09c0000 c0a7a1e4 c09c8938 c09c89b4 00000000 60000093 c09c1fb0
> >> [   55.718423] 1fa0: c008a2e4 c00926cc 60000013 ffffffff
> >> [   55.718433] [<c0630964>] (__irq_svc) from [<c00926cc>] (cpu_startup_entry+0x100/0x1f4)
> >> [   55.718444] [<c00926cc>] (cpu_startup_entry) from [<c0901ac4>] (start_kernel+0x324/0x388)
> >>
> >> Signed-off-by: Roger Quadros <rogerq@ti.com>
> >> ---
> >>  drivers/usb/dwc3/gadget.c | 8 +++++++-
> >>  1 file changed, 7 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> >> index 3818b26..bc15b54 100644
> >> --- a/drivers/usb/dwc3/gadget.c
> >> +++ b/drivers/usb/dwc3/gadget.c
> >> @@ -2741,7 +2741,13 @@ int dwc3_gadget_prepare(struct dwc3 *dwc)
> > 
> > there is no more dwc3_gadget_prepare(), please rebase on 'next'.
> 
> right.
> 
> > 
> >>  {
> >>  	if (dwc->pullups_connected) {
> >>  		dwc3_gadget_disable_irq(dwc);
> >> -		dwc3_gadget_run_stop(dwc, true, true);
> >> +		if (dwc->has_hibernation) {
> >> +			dwc3_gadget_run_stop(dwc, true, true);
> >> +		} else {
> >> +			dwc3_gadget_run_stop(dwc, false, true);
> >> +			/* remember to connect back on resume */
> >> +			dwc->pullups_connected = true;
> >> +		}
> > 
> > Another thing you probably want to do is make sure there is nothing
> > pending on our request list because if there is, then we need to wait
> > for any in-flight transfers to complete before disconnecting.
> 
> shouldn't that check be done in dwc3_gadget_run_stop()?

no, gadget drivers only disconnect pullups when they know there's
nothing pending. And sometimes, we actually want to break such transfers
to see how the thing would behave. Only suspend/resume needs to make
transfers complete before hand.

> > I also wonder if current code isn't really fragile... I mean, when you
> > clear run_stop bit, you should notify the gadget by means of
> > ->disconnect() and so on... But since we can't test this with mainline,
> > then it's difficult to tell.
> > 
> that is true.

Not sure what to do with this patch :-p
Roger Quadros Nov. 12, 2014, 3:40 p.m. | #4
On 11/12/2014 05:36 PM, Felipe Balbi wrote:
> Hi,
> 
> On Wed, Nov 12, 2014 at 05:32:00PM +0200, Roger Quadros wrote:
>> On 11/12/2014 05:08 PM, Felipe Balbi wrote:
>>> On Wed, Nov 12, 2014 at 04:58:16PM +0200, Roger Quadros wrote:
>>>> On TI SoCs (e.g. DRA7) we don't support the DWC3 hibernation feature.
>>>> We need to stop the gadget controller while system suspend
>>>> else it results in L3 Bus errors on resume with broken
>>>> USB gadget on J6-evm.
>>>>
>>>> [   55.718226] WARNING: CPU: 0 PID: 0 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x224/0x31c()
>>>> [   55.718232] 44000000.ocp:L3 Custom Error: MASTER USB3 TARGET GPMC (Idle): Data Access in User mode during Functional access
>>>> [   55.718263] Modules linked in: usb_f_ss_lb g_zero libcomposite configfs xhci_hcd btwilink bluetooth dwc3 6lowpan_iphc m25p80 dwc3_omap omap_remoteproc
>>>> [   55.718271] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.19-02011-g3ece3ca-dirty #658
>>>> [   55.718290] [<c0016090>] (unwind_backtrace) from [<c0012060>] (show_stack+0x10/0x14)
>>>> [   55.718302] [<c0012060>] (show_stack) from [<c062a2e4>] (dump_stack+0x78/0x94)
>>>> [   55.718315] [<c062a2e4>] (dump_stack) from [<c0043bc4>] (warn_slowpath_common+0x6c/0x90)
>>>> [   55.718325] [<c0043bc4>] (warn_slowpath_common) from [<c0043c7c>] (warn_slowpath_fmt+0x30/0x40)
>>>> [   55.718336] [<c0043c7c>] (warn_slowpath_fmt) from [<c030fb24>] (l3_interrupt_handler+0x224/0x31c)
>>>> [   55.718348] [<c030fb24>] (l3_interrupt_handler) from [<c0093010>] (handle_irq_event_percpu+0x5c/0x23c)
>>>> [   55.718358] [<c0093010>] (handle_irq_event_percpu) from [<c009322c>] (handle_irq_event+0x3c/0x5c)
>>>> [   55.718367] [<c009322c>] (handle_irq_event) from [<c0096160>] (handle_fasteoi_irq+0x98/0x158)
>>>> [   55.718377] [<c0096160>] (handle_fasteoi_irq) from [<c00929dc>] (generic_handle_irq+0x20/0x30)
>>>> [   55.718385] [<c00929dc>] (generic_handle_irq) from [<c000eea8>] (handle_IRQ+0x4c/0xb0)
>>>> [   55.718393] [<c000eea8>] (handle_IRQ) from [<c0008638>] (gic_handle_irq+0x28/0x5c)
>>>> [   55.718402] [<c0008638>] (gic_handle_irq) from [<c0630964>] (__irq_svc+0x44/0x5c)
>>>> [   55.718406] Exception stack(0xc09c1f68 to 0xc09c1fb0)
>>>> [   55.718412] 1f60:                   00000001 00000001 00000000 00000000 c09c0000 00000000
>>>> [   55.718418] 1f80: c09c0000 c09c0000 c0a7a1e4 c09c8938 c09c89b4 00000000 60000093 c09c1fb0
>>>> [   55.718423] 1fa0: c008a2e4 c00926cc 60000013 ffffffff
>>>> [   55.718433] [<c0630964>] (__irq_svc) from [<c00926cc>] (cpu_startup_entry+0x100/0x1f4)
>>>> [   55.718444] [<c00926cc>] (cpu_startup_entry) from [<c0901ac4>] (start_kernel+0x324/0x388)
>>>>
>>>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>>>> ---
>>>>  drivers/usb/dwc3/gadget.c | 8 +++++++-
>>>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>>>> index 3818b26..bc15b54 100644
>>>> --- a/drivers/usb/dwc3/gadget.c
>>>> +++ b/drivers/usb/dwc3/gadget.c
>>>> @@ -2741,7 +2741,13 @@ int dwc3_gadget_prepare(struct dwc3 *dwc)
>>>
>>> there is no more dwc3_gadget_prepare(), please rebase on 'next'.
>>
>> right.
>>
>>>
>>>>  {
>>>>  	if (dwc->pullups_connected) {
>>>>  		dwc3_gadget_disable_irq(dwc);
>>>> -		dwc3_gadget_run_stop(dwc, true, true);
>>>> +		if (dwc->has_hibernation) {
>>>> +			dwc3_gadget_run_stop(dwc, true, true);
>>>> +		} else {
>>>> +			dwc3_gadget_run_stop(dwc, false, true);
>>>> +			/* remember to connect back on resume */
>>>> +			dwc->pullups_connected = true;
>>>> +		}
>>>
>>> Another thing you probably want to do is make sure there is nothing
>>> pending on our request list because if there is, then we need to wait
>>> for any in-flight transfers to complete before disconnecting.
>>
>> shouldn't that check be done in dwc3_gadget_run_stop()?
> 
> no, gadget drivers only disconnect pullups when they know there's
> nothing pending. And sometimes, we actually want to break such transfers
> to see how the thing would behave. Only suspend/resume needs to make
> transfers complete before hand.
> 
>>> I also wonder if current code isn't really fragile... I mean, when you
>>> clear run_stop bit, you should notify the gadget by means of
>>> ->disconnect() and so on... But since we can't test this with mainline,
>>> then it's difficult to tell.
>>>
>> that is true.
> 
> Not sure what to do with this patch :-p
> 
:). Maybe we can wait till we have suspend/resume working in mainline.

cheers,
-roger
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Felipe Balbi Nov. 12, 2014, 3:54 p.m. | #5
On Wed, Nov 12, 2014 at 05:40:59PM +0200, Roger Quadros wrote:
> On 11/12/2014 05:36 PM, Felipe Balbi wrote:
> > Hi,
> > 
> > On Wed, Nov 12, 2014 at 05:32:00PM +0200, Roger Quadros wrote:
> >> On 11/12/2014 05:08 PM, Felipe Balbi wrote:
> >>> On Wed, Nov 12, 2014 at 04:58:16PM +0200, Roger Quadros wrote:
> >>>> On TI SoCs (e.g. DRA7) we don't support the DWC3 hibernation feature.
> >>>> We need to stop the gadget controller while system suspend
> >>>> else it results in L3 Bus errors on resume with broken
> >>>> USB gadget on J6-evm.
> >>>>
> >>>> [   55.718226] WARNING: CPU: 0 PID: 0 at drivers/bus/omap_l3_noc.c:147 l3_interrupt_handler+0x224/0x31c()
> >>>> [   55.718232] 44000000.ocp:L3 Custom Error: MASTER USB3 TARGET GPMC (Idle): Data Access in User mode during Functional access
> >>>> [   55.718263] Modules linked in: usb_f_ss_lb g_zero libcomposite configfs xhci_hcd btwilink bluetooth dwc3 6lowpan_iphc m25p80 dwc3_omap omap_remoteproc
> >>>> [   55.718271] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.19-02011-g3ece3ca-dirty #658
> >>>> [   55.718290] [<c0016090>] (unwind_backtrace) from [<c0012060>] (show_stack+0x10/0x14)
> >>>> [   55.718302] [<c0012060>] (show_stack) from [<c062a2e4>] (dump_stack+0x78/0x94)
> >>>> [   55.718315] [<c062a2e4>] (dump_stack) from [<c0043bc4>] (warn_slowpath_common+0x6c/0x90)
> >>>> [   55.718325] [<c0043bc4>] (warn_slowpath_common) from [<c0043c7c>] (warn_slowpath_fmt+0x30/0x40)
> >>>> [   55.718336] [<c0043c7c>] (warn_slowpath_fmt) from [<c030fb24>] (l3_interrupt_handler+0x224/0x31c)
> >>>> [   55.718348] [<c030fb24>] (l3_interrupt_handler) from [<c0093010>] (handle_irq_event_percpu+0x5c/0x23c)
> >>>> [   55.718358] [<c0093010>] (handle_irq_event_percpu) from [<c009322c>] (handle_irq_event+0x3c/0x5c)
> >>>> [   55.718367] [<c009322c>] (handle_irq_event) from [<c0096160>] (handle_fasteoi_irq+0x98/0x158)
> >>>> [   55.718377] [<c0096160>] (handle_fasteoi_irq) from [<c00929dc>] (generic_handle_irq+0x20/0x30)
> >>>> [   55.718385] [<c00929dc>] (generic_handle_irq) from [<c000eea8>] (handle_IRQ+0x4c/0xb0)
> >>>> [   55.718393] [<c000eea8>] (handle_IRQ) from [<c0008638>] (gic_handle_irq+0x28/0x5c)
> >>>> [   55.718402] [<c0008638>] (gic_handle_irq) from [<c0630964>] (__irq_svc+0x44/0x5c)
> >>>> [   55.718406] Exception stack(0xc09c1f68 to 0xc09c1fb0)
> >>>> [   55.718412] 1f60:                   00000001 00000001 00000000 00000000 c09c0000 00000000
> >>>> [   55.718418] 1f80: c09c0000 c09c0000 c0a7a1e4 c09c8938 c09c89b4 00000000 60000093 c09c1fb0
> >>>> [   55.718423] 1fa0: c008a2e4 c00926cc 60000013 ffffffff
> >>>> [   55.718433] [<c0630964>] (__irq_svc) from [<c00926cc>] (cpu_startup_entry+0x100/0x1f4)
> >>>> [   55.718444] [<c00926cc>] (cpu_startup_entry) from [<c0901ac4>] (start_kernel+0x324/0x388)
> >>>>
> >>>> Signed-off-by: Roger Quadros <rogerq@ti.com>
> >>>> ---
> >>>>  drivers/usb/dwc3/gadget.c | 8 +++++++-
> >>>>  1 file changed, 7 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> >>>> index 3818b26..bc15b54 100644
> >>>> --- a/drivers/usb/dwc3/gadget.c
> >>>> +++ b/drivers/usb/dwc3/gadget.c
> >>>> @@ -2741,7 +2741,13 @@ int dwc3_gadget_prepare(struct dwc3 *dwc)
> >>>
> >>> there is no more dwc3_gadget_prepare(), please rebase on 'next'.
> >>
> >> right.
> >>
> >>>
> >>>>  {
> >>>>  	if (dwc->pullups_connected) {
> >>>>  		dwc3_gadget_disable_irq(dwc);
> >>>> -		dwc3_gadget_run_stop(dwc, true, true);
> >>>> +		if (dwc->has_hibernation) {
> >>>> +			dwc3_gadget_run_stop(dwc, true, true);
> >>>> +		} else {
> >>>> +			dwc3_gadget_run_stop(dwc, false, true);
> >>>> +			/* remember to connect back on resume */
> >>>> +			dwc->pullups_connected = true;
> >>>> +		}
> >>>
> >>> Another thing you probably want to do is make sure there is nothing
> >>> pending on our request list because if there is, then we need to wait
> >>> for any in-flight transfers to complete before disconnecting.
> >>
> >> shouldn't that check be done in dwc3_gadget_run_stop()?
> > 
> > no, gadget drivers only disconnect pullups when they know there's
> > nothing pending. And sometimes, we actually want to break such transfers
> > to see how the thing would behave. Only suspend/resume needs to make
> > transfers complete before hand.
> > 
> >>> I also wonder if current code isn't really fragile... I mean, when you
> >>> clear run_stop bit, you should notify the gadget by means of
> >>> ->disconnect() and so on... But since we can't test this with mainline,
> >>> then it's difficult to tell.
> >>>
> >> that is true.
> > 
> > Not sure what to do with this patch :-p
> > 
> :). Maybe we can wait till we have suspend/resume working in mainline.

Perhaps... hopefully we won't forget about this :-)

Patch

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 3818b26..bc15b54 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2741,7 +2741,13 @@  int dwc3_gadget_prepare(struct dwc3 *dwc)
 {
 	if (dwc->pullups_connected) {
 		dwc3_gadget_disable_irq(dwc);
-		dwc3_gadget_run_stop(dwc, true, true);
+		if (dwc->has_hibernation) {
+			dwc3_gadget_run_stop(dwc, true, true);
+		} else {
+			dwc3_gadget_run_stop(dwc, false, true);
+			/* remember to connect back on resume */
+			dwc->pullups_connected = true;
+		}
 	}
 
 	return 0;