| Message ID | 1441203864-15786-9-git-send-email-rogerq@ti.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Sep 02, 2015 at 05:24:23PM +0300, Roger Quadros wrote: > There is a race happening during dwc3_drd_init() that causes > otg events to get disabled. This is what happens. > > dwc3_otg_irq() happens immediately when PRTCAP is set to OTG, > even though OEVTEN is 0. This is because BIT 31 IRQ of > OEVT can't be disabled by OEVTEN. > We configure OEVTEN in dwc3_otg_init() but dwc3_otg_irq() has > already saved OEVTEN as 0 into dwc->oevten. So finally when > dwc3_irq_thread_irq() is called we save 0 into OEVTEN > thus disabling OTG irqs forever. > > We fix this by disabling IRQs when configuring OEVTEN in > dwc3_otg_init(). > > Signed-off-by: Roger Quadros <rogerq@ti.com> can't you just merge this patch into the one which introduced the bug to start with ? > --- > drivers/usb/dwc3/core.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c > index 684010c..654aebf 100644 > --- a/drivers/usb/dwc3/core.c > +++ b/drivers/usb/dwc3/core.c > @@ -921,6 +921,7 @@ static int dwc3_drd_init(struct dwc3 *dwc) > int ret, id, vbus; > struct usb_otg_caps *otgcaps = &dwc->otg_config.otg_caps; > u32 reg; > + unsigned long flags; > > otgcaps->otg_rev = 0; > otgcaps->hnp_support = false; > @@ -993,6 +994,8 @@ try_otg_core: > goto error; > } > > + spin_lock_irqsave(&dwc->lock, flags); > + > /* we need to set OTG to get events from OTG core */ > dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG); > /* GUSB2PHYCFG0.SusPHY=0 */ > @@ -1018,6 +1021,8 @@ try_otg_core: > /* OCTL.PeriMode = 1 */ > dwc3_writel(dwc->regs, DWC3_OCTL, DWC3_OCTL_PERIMODE); > > + spin_unlock_irqrestore(&dwc->lock, flags); > + > dwc3_otg_fsm_sync(dwc); > usb_otg_sync_inputs(dwc->fsm); > > -- > 2.1.4 >
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 02/09/15 17:47, Felipe Balbi wrote: > On Wed, Sep 02, 2015 at 05:24:23PM +0300, Roger Quadros wrote: >> There is a race happening during dwc3_drd_init() that causes >> otg events to get disabled. This is what happens. >> >> dwc3_otg_irq() happens immediately when PRTCAP is set to OTG, >> even though OEVTEN is 0. This is because BIT 31 IRQ of >> OEVT can't be disabled by OEVTEN. >> We configure OEVTEN in dwc3_otg_init() but dwc3_otg_irq() has >> already saved OEVTEN as 0 into dwc->oevten. So finally when >> dwc3_irq_thread_irq() is called we save 0 into OEVTEN >> thus disabling OTG irqs forever. >> >> We fix this by disabling IRQs when configuring OEVTEN in >> dwc3_otg_init(). >> >> Signed-off-by: Roger Quadros <rogerq@ti.com> > > can't you just merge this patch into the one which introduced the bug to > start with ? Yes, I'll do that. > >> --- >> drivers/usb/dwc3/core.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c >> index 684010c..654aebf 100644 >> --- a/drivers/usb/dwc3/core.c >> +++ b/drivers/usb/dwc3/core.c >> @@ -921,6 +921,7 @@ static int dwc3_drd_init(struct dwc3 *dwc) >> int ret, id, vbus; >> struct usb_otg_caps *otgcaps = &dwc->otg_config.otg_caps; >> u32 reg; >> + unsigned long flags; >> >> otgcaps->otg_rev = 0; >> otgcaps->hnp_support = false; >> @@ -993,6 +994,8 @@ try_otg_core: >> goto error; >> } >> >> + spin_lock_irqsave(&dwc->lock, flags); >> + >> /* we need to set OTG to get events from OTG core */ >> dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG); >> /* GUSB2PHYCFG0.SusPHY=0 */ >> @@ -1018,6 +1021,8 @@ try_otg_core: >> /* OCTL.PeriMode = 1 */ >> dwc3_writel(dwc->regs, DWC3_OCTL, DWC3_OCTL_PERIMODE); >> >> + spin_unlock_irqrestore(&dwc->lock, flags); >> + >> dwc3_otg_fsm_sync(dwc); >> usb_otg_sync_inputs(dwc->fsm); >> >> -- >> 2.1.4 >> > - -- cheers, - -roger -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJV6FEnAAoJENJaa9O+djCTSjgQALL73OtdfKAWte2JFxsw1PVT Xeh+ec7FJqNCKb2TwTSgnnWp6BxapbAlkK3kSwhsbgZvZLGtf3IC+xPHWNCs4dZs uCs9oDPC/oAiYBnN3gYZxBFuhe1fsFEuS7aFIzrvKD/+tnXmd0IQ5Yu3k06VDXIM jf/034Wep9AK44fyPy0sLKET1J6/UMvjxvUpEyxj9elbvs+GqzD9qR/GF6Ob8q6d 5f7y4ajMBCgyoC/wpIXDIJi7yqH1MUZq8bdC+7BKyc8Fz7kzVSpU2SL0BSRMU7Jn Mzyx25WbWy1mXkfdgOjXtxx6MH5gV6jIIvqobyXXrK/e0z3kU6OeFprbubsOAvmC fcgRkOrfr1O7/G5Gm7mhU5kLSZF6kvf6MoDPGCd/TbP4OgfYcPiTj5O020qDbRxZ Hfuy/5Xk1oxR2aui1q9ycCWrpSA4L+B4fSpDXUznZw755BhhPnVeoYlXUfcb2sI+ YPNs6cLeX95I27AoMpK0wjMptmswaKcDmwv50mjK0kXgUcnVGs6z7YxSIJ2eAxPV OpYLwVTfJiqoeJMscHvqoipwjlHqq4xS780SbzgZTDFOk2Ik7l0B6mNoL9CgaaXa LVCBEywdWo+9os4b3JRrjDSqqdOMhBVaO0GvtiZZqfF7mOTmJHF/yFAODBw/CLXi jAmBC/nM3M32CJphQQ1J =z7cJ -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 684010c..654aebf 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -921,6 +921,7 @@ static int dwc3_drd_init(struct dwc3 *dwc) int ret, id, vbus; struct usb_otg_caps *otgcaps = &dwc->otg_config.otg_caps; u32 reg; + unsigned long flags; otgcaps->otg_rev = 0; otgcaps->hnp_support = false; @@ -993,6 +994,8 @@ try_otg_core: goto error; } + spin_lock_irqsave(&dwc->lock, flags); + /* we need to set OTG to get events from OTG core */ dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG); /* GUSB2PHYCFG0.SusPHY=0 */ @@ -1018,6 +1021,8 @@ try_otg_core: /* OCTL.PeriMode = 1 */ dwc3_writel(dwc->regs, DWC3_OCTL, DWC3_OCTL_PERIMODE); + spin_unlock_irqrestore(&dwc->lock, flags); + dwc3_otg_fsm_sync(dwc); usb_otg_sync_inputs(dwc->fsm);
There is a race happening during dwc3_drd_init() that causes otg events to get disabled. This is what happens. dwc3_otg_irq() happens immediately when PRTCAP is set to OTG, even though OEVTEN is 0. This is because BIT 31 IRQ of OEVT can't be disabled by OEVTEN. We configure OEVTEN in dwc3_otg_init() but dwc3_otg_irq() has already saved OEVTEN as 0 into dwc->oevten. So finally when dwc3_irq_thread_irq() is called we save 0 into OEVTEN thus disabling OTG irqs forever. We fix this by disabling IRQs when configuring OEVTEN in dwc3_otg_init(). Signed-off-by: Roger Quadros <rogerq@ti.com> --- drivers/usb/dwc3/core.c | 5 +++++ 1 file changed, 5 insertions(+)