| Message ID | 20230622025739.13934-1-aarongt.shen@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | usb: ohci-at91: Fix the unhandle interrupt when resume | expand |
On Fri, Jun 23, 2023 at 23:52:53PM GMT+8, Alan Stern wrote: > On Fri, Jun 23, 2023 at 11:44:04AM +0800, Guiting Shen wrote: >> >> >> On Thu,Jun 22,2023 at 22:29:43PM GMT+8, Alan Stern wrote: >>> On Thu, Jun 22, 2023 at 10:57:39AM +0800, Guiting Shen wrote: >>>> The ohci_hcd_at91_drv_suspend() sets ohci->rh_state to OHCI_RH_HALTED when >>>> suspend which will let the ohci_irq() skip the interrupt after resume. And >>>> nobody to handle this interrupt. >>>> >>>> Set the ohci->rh_state to OHCI_RH_SUSPEND instead of OHCI_RH_HALTED when >>>> suspend to fix it. >>>> >>>> Signed-off-by: Guiting Shen <aarongt.shen@gmail.com> >>>> --- >>>> drivers/usb/host/ohci-at91.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c >>>> index b9ce8d80f20b..7a970e573668 100644 >>>> --- a/drivers/usb/host/ohci-at91.c >>>> +++ b/drivers/usb/host/ohci-at91.c >>>> @@ -645,7 +645,7 @@ ohci_hcd_at91_drv_suspend(struct device *dev) >>>> * REVISIT: some boards will be able to turn VBUS off... >>>> */ >>>> if (!ohci_at91->wakeup) { >>>> - ohci->rh_state = OHCI_RH_HALTED; >>>> + ohci->rh_state = OHCI_RH_SUSPENDED; >>> >>> It looks like this change ignores the comment immediately above it >>> (just before the start of this hunk). >>> >>> If you want to find a way to handle IRQs better after the controller >>> resumes, maybe you should change the resume routine instead of the >>> suspend routine. >>> >>> Alan Stern >> >> The comment which was added with commit-id 0365ee0a8f745 may be outdated >> because ohci_suspend() and ohci_at91_port_suspend() is used to suspend >> instead of setting ohci->rh_state to OHCI_RH_HALTED. > > The comment says nothing about ohci->rh_state; it talks about the > integrated transceivers and the 48 MHz clock. I don't see why you would > think the comment is outdated. > The comment says the reason to discard connection state by reset, but I don't see any reset operation at ohci-at91 suspend/resume routine in source code.And ohci_suspend() disable irq emission and mark HW unaccessible maybe do the same effect as set ohci->rh_state to OHCI_RH_HALTED to discard connection state which I think the comment is outdated. >> What's more, I found that only ohci-at91 driver to set the ohci->rh_state >> which may be unnessory because the ohci_suspend() disable irq emission and >> mark HW unaccessible and ohci_at91_port_suspend() suspend the controller. >> >> Is it really need to set ohci->rh_state in ohci_hcd_at91_drv_suspend()? >> >> It maybe confused to set ohci->rh_state to OHCI_RH_SUSPEND in resume >> routine. > > I'm not really sure what that assignment was intended to accomplish, but > maybe it was meant to force a reset when the controller resumes. > > You could get the same result by leaving ohci->rh_state set to > OHCI_RH_SUSPENDED but changing ohci_hcd_at91_drv_resume(). Instead of > calling ohci_resume(hcd, false), have it call: > > ohci_resume(hcd, !ohci_at91->wakeup); > > That way, if the wakeup flag is clear and the clock was stopped, > ohci_resume() will call ohci_usb_reset(). You should also add a comment > explaining the reason. > > I can't test this because I don't have the AT91 hardware. > It works by your methods to force a reset in my sama5d3 soc hardware. And I found that the ohci->rh_state was already OHCI_RH_SUSPEND before set it OHCI_RH_HALTED in suspend.So the question is whether to set it OHCI_RH_HALETED in ohci-at91 suspend routine. It also works by comment the ohci->rh_state = OHCI_RH_HALTED in suspend routine.But I think it is safer to use your methods. Do you have any suggestion on it before I send v2 patch latter.
On Sun, Jun 25, 2023 at 12:01:12PM +0800, Guiting Shen wrote: > On Fri, Jun 23, 2023 at 23:52:53PM GMT+8, Alan Stern wrote: > >> The comment which was added with commit-id 0365ee0a8f745 may be outdated > >> because ohci_suspend() and ohci_at91_port_suspend() is used to suspend > >> instead of setting ohci->rh_state to OHCI_RH_HALTED. > > > > The comment says nothing about ohci->rh_state; it talks about the > > integrated transceivers and the 48 MHz clock. I don't see why you would > > think the comment is outdated. > > > > The comment says the reason to discard connection state by reset, but I > don't see any reset operation at ohci-at91 suspend/resume routine in > source code.And ohci_suspend() disable irq emission and mark HW > unaccessible maybe do the same effect as set ohci->rh_state to > OHCI_RH_HALTED to discard connection state which I think the comment is > outdated. No, it doesn't do the same. An actual reset is needed. > >> What's more, I found that only ohci-at91 driver to set the ohci->rh_state > >> which may be unnessory because the ohci_suspend() disable irq emission and > >> mark HW unaccessible and ohci_at91_port_suspend() suspend the controller. > >> > >> Is it really need to set ohci->rh_state in ohci_hcd_at91_drv_suspend()? > >> > >> It maybe confused to set ohci->rh_state to OHCI_RH_SUSPEND in resume > >> routine. > > > > I'm not really sure what that assignment was intended to accomplish, but > > maybe it was meant to force a reset when the controller resumes. > > > > You could get the same result by leaving ohci->rh_state set to > > OHCI_RH_SUSPENDED but changing ohci_hcd_at91_drv_resume(). Instead of > > calling ohci_resume(hcd, false), have it call: > > > > ohci_resume(hcd, !ohci_at91->wakeup); > > > > That way, if the wakeup flag is clear and the clock was stopped, > > ohci_resume() will call ohci_usb_reset(). You should also add a comment > > explaining the reason. > > > > I can't test this because I don't have the AT91 hardware. > > > > It works by your methods to force a reset in my sama5d3 soc hardware. > And I found that the ohci->rh_state was already OHCI_RH_SUSPEND before > set it OHCI_RH_HALTED in suspend.So the question is whether to set it > OHCI_RH_HALETED in ohci-at91 suspend routine. > > It also works by comment the ohci->rh_state = OHCI_RH_HALTED in suspend > routine.But I think it is safer to use your methods. > > Do you have any suggestion on it before I send v2 patch latter. No suggestions now. Submit your v2 patch and then maybe I'll have something more to say. Alan Stern
diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c index b9ce8d80f20b..7a970e573668 100644 --- a/drivers/usb/host/ohci-at91.c +++ b/drivers/usb/host/ohci-at91.c @@ -645,7 +645,7 @@ ohci_hcd_at91_drv_suspend(struct device *dev) * REVISIT: some boards will be able to turn VBUS off... */ if (!ohci_at91->wakeup) { - ohci->rh_state = OHCI_RH_HALTED; + ohci->rh_state = OHCI_RH_SUSPENDED; /* flush the writes */ (void) ohci_readl (ohci, &ohci->regs->control);
The ohci_hcd_at91_drv_suspend() sets ohci->rh_state to OHCI_RH_HALTED when suspend which will let the ohci_irq() skip the interrupt after resume. And nobody to handle this interrupt. Set the ohci->rh_state to OHCI_RH_SUSPEND instead of OHCI_RH_HALTED when suspend to fix it. Signed-off-by: Guiting Shen <aarongt.shen@gmail.com> --- drivers/usb/host/ohci-at91.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)