| Message ID | 20201021181803.79650-1-john.stultz@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC] usb: dwc3: Add quirk to trigger a GCTL soft reset for Hisilicon Kirin Soc Platform | expand |
John Stultz wrote: > From: Yu Chen <chenyu56@huawei.com> > > With the current dwc3 code on the HiKey960 we often see the > COREIDLE flag get stuck off in __dwc3_gadget_start(), which > seems to prevent the reset irq and causes the USB gadget to > fail to initialize. > > We had seen occasional initialization failures with older > kernels but with recent 5.x era kernels it seemed to be becoming > much more common, so I dug back through some older trees and > realized I dropped this quirk from Yu Chen during upstreaming > as I couldn't provide a proper rational for it and it didn't > seem to be necessary. I now realize I was wrong. > > On the upside, I can now understand more why such a quirk is > needed. This shouldn't be a quirk. It's part of the programming guide when switching mode in DRD. I don't know how we missed this. > > So to address a quirk in the DesignWare USB3 DRD Core of > Hisilicon Kirin SoCs, this patch adds a quirk flag which > executes a GCTL soft reset when we switch modes. > > Cc: Felipe Balbi <balbi@kernel.org> > Cc: Tejas Joglekar <tejas.joglekar@synopsys.com> > Cc: Yang Fei <fei.yang@intel.com> > Cc: YongQin Liu <yongqin.liu@linaro.org> > Cc: Andrzej Pietrasiewicz <andrzej.p@collabora.com> > Cc: Thinh Nguyen <thinhn@synopsys.com> > Cc: Jun Li <lijun.kernel@gmail.com> > Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: linux-usb@vger.kernel.org > Cc: devicetree@vger.kernel.org > Signed-off-by: Yu Chen <chenyu56@huawei.com> > Signed-off-by: John Stultz <john.stultz@linaro.org> > --- > .../devicetree/bindings/usb/dwc3.txt | 3 +++ > drivers/usb/dwc3/core.c | 19 +++++++++++++++++++ > drivers/usb/dwc3/core.h | 1 + > 3 files changed, 23 insertions(+) > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt > index 1aae2b6160c1..f435bae0f172 100644 > --- a/Documentation/devicetree/bindings/usb/dwc3.txt > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt > @@ -81,6 +81,9 @@ Optional properties: > - snps,dis-split-quirk: when set, change the way URBs are handled by the > driver. Needed to avoid -EPROTO errors with usbhid > on some devices (Hikey 970). > + - snps,gctl-reset-quirk: When set, execute a soft reset on mode changes. > + Needed to avoid COREIDLE getting stuck off and the > + gadget to fail to initialize (HiKey960). > - snps,is-utmi-l1-suspend: true when DWC3 asserts output signal > utmi_l1_suspend_n, false when asserts utmi_sleep_n > - snps,hird-threshold: HIRD threshold > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c > index bdf0925da6b6..b138c67e3892 100644 > --- a/drivers/usb/dwc3/core.c > +++ b/drivers/usb/dwc3/core.c > @@ -114,6 +114,19 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode) > dwc->current_dr_role = mode; > } > > +static void dwc3_gctl_core_soft_reset(struct dwc3 *dwc) > +{ > + int reg; > + > + reg = dwc3_readl(dwc->regs, DWC3_GCTL); > + reg |= (DWC3_GCTL_CORESOFTRESET); > + dwc3_writel(dwc->regs, DWC3_GCTL, reg); > + > + reg = dwc3_readl(dwc->regs, DWC3_GCTL); > + reg &= ~(DWC3_GCTL_CORESOFTRESET); > + dwc3_writel(dwc->regs, DWC3_GCTL, reg); > +} > + > static void __dwc3_set_mode(struct work_struct *work) > { > struct dwc3 *dwc = work_to_dwc(work); > @@ -178,6 +191,10 @@ static void __dwc3_set_mode(struct work_struct *work) > } > break; > case DWC3_GCTL_PRTCAP_DEVICE: > + /* Execute a GCTL Core Soft Reset when switch mode */ > + if (dwc->gctl_reset_quirk) > + dwc3_gctl_core_soft_reset(dwc); > + This should be done before dwc3_set_prtcap(), and this applies when switching from device to host mode also. Make sure to check if the controller is DRD before doing this. > dwc3_event_buffers_setup(dwc); > > if (dwc->usb2_phy) > @@ -1357,6 +1374,8 @@ static void dwc3_get_properties(struct dwc3 *dwc) > > dwc->dis_split_quirk = device_property_read_bool(dev, > "snps,dis-split-quirk"); > + dwc->gctl_reset_quirk = device_property_read_bool(dev, > + "snps,gctl-reset-quirk"); > > dwc->lpm_nyet_threshold = lpm_nyet_threshold; > dwc->tx_de_emphasis = tx_de_emphasis; > diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h > index 74323b10a64a..993f243aedc8 100644 > --- a/drivers/usb/dwc3/core.h > +++ b/drivers/usb/dwc3/core.h > @@ -1252,6 +1252,7 @@ struct dwc3 { > unsigned dis_metastability_quirk:1; > > unsigned dis_split_quirk:1; > + unsigned gctl_reset_quirk:1; > > u16 imod_interval; > }; BR, Thinh
On Wed, Oct 21, 2020 at 12:14 PM Thinh Nguyen <Thinh.Nguyen@synopsys.com> wrote: > > John Stultz wrote: > > From: Yu Chen <chenyu56@huawei.com> > > > > With the current dwc3 code on the HiKey960 we often see the > > COREIDLE flag get stuck off in __dwc3_gadget_start(), which > > seems to prevent the reset irq and causes the USB gadget to > > fail to initialize. > > > > We had seen occasional initialization failures with older > > kernels but with recent 5.x era kernels it seemed to be becoming > > much more common, so I dug back through some older trees and > > realized I dropped this quirk from Yu Chen during upstreaming > > as I couldn't provide a proper rational for it and it didn't > > seem to be necessary. I now realize I was wrong. > > > > On the upside, I can now understand more why such a quirk is > > needed. > > This shouldn't be a quirk. It's part of the programming guide when > switching mode in DRD. I don't know how we missed this. Ah! That's great, as it should simplify the patch a bit and avoid introducing another dt bindings! > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c > > index bdf0925da6b6..b138c67e3892 100644 > > --- a/drivers/usb/dwc3/core.c > > +++ b/drivers/usb/dwc3/core.c > > @@ -114,6 +114,19 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode) > > dwc->current_dr_role = mode; > > } > > > > +static void dwc3_gctl_core_soft_reset(struct dwc3 *dwc) > > +{ > > + int reg; > > + > > + reg = dwc3_readl(dwc->regs, DWC3_GCTL); > > + reg |= (DWC3_GCTL_CORESOFTRESET); > > + dwc3_writel(dwc->regs, DWC3_GCTL, reg); > > + > > + reg = dwc3_readl(dwc->regs, DWC3_GCTL); > > + reg &= ~(DWC3_GCTL_CORESOFTRESET); > > + dwc3_writel(dwc->regs, DWC3_GCTL, reg); > > +} > > + > > static void __dwc3_set_mode(struct work_struct *work) > > { > > struct dwc3 *dwc = work_to_dwc(work); > > @@ -178,6 +191,10 @@ static void __dwc3_set_mode(struct work_struct *work) > > } > > break; > > case DWC3_GCTL_PRTCAP_DEVICE: > > + /* Execute a GCTL Core Soft Reset when switch mode */ > > + if (dwc->gctl_reset_quirk) > > + dwc3_gctl_core_soft_reset(dwc); > > + > > This should be done before dwc3_set_prtcap(), and this applies when > switching from device to host mode also. Make sure to check if the > controller is DRD before doing this. Sorry, by checking that the controller is DRD, I'm not sure exactly what you mean. Checking DWC3_GHWPARAMS0_MODE_DRD? Or something else? Thanks so much for the review and feedback! -john
diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt index 1aae2b6160c1..f435bae0f172 100644 --- a/Documentation/devicetree/bindings/usb/dwc3.txt +++ b/Documentation/devicetree/bindings/usb/dwc3.txt @@ -81,6 +81,9 @@ Optional properties: - snps,dis-split-quirk: when set, change the way URBs are handled by the driver. Needed to avoid -EPROTO errors with usbhid on some devices (Hikey 970). + - snps,gctl-reset-quirk: When set, execute a soft reset on mode changes. + Needed to avoid COREIDLE getting stuck off and the + gadget to fail to initialize (HiKey960). - snps,is-utmi-l1-suspend: true when DWC3 asserts output signal utmi_l1_suspend_n, false when asserts utmi_sleep_n - snps,hird-threshold: HIRD threshold diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index bdf0925da6b6..b138c67e3892 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -114,6 +114,19 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode) dwc->current_dr_role = mode; } +static void dwc3_gctl_core_soft_reset(struct dwc3 *dwc) +{ + int reg; + + reg = dwc3_readl(dwc->regs, DWC3_GCTL); + reg |= (DWC3_GCTL_CORESOFTRESET); + dwc3_writel(dwc->regs, DWC3_GCTL, reg); + + reg = dwc3_readl(dwc->regs, DWC3_GCTL); + reg &= ~(DWC3_GCTL_CORESOFTRESET); + dwc3_writel(dwc->regs, DWC3_GCTL, reg); +} + static void __dwc3_set_mode(struct work_struct *work) { struct dwc3 *dwc = work_to_dwc(work); @@ -178,6 +191,10 @@ static void __dwc3_set_mode(struct work_struct *work) } break; case DWC3_GCTL_PRTCAP_DEVICE: + /* Execute a GCTL Core Soft Reset when switch mode */ + if (dwc->gctl_reset_quirk) + dwc3_gctl_core_soft_reset(dwc); + dwc3_event_buffers_setup(dwc); if (dwc->usb2_phy) @@ -1357,6 +1374,8 @@ static void dwc3_get_properties(struct dwc3 *dwc) dwc->dis_split_quirk = device_property_read_bool(dev, "snps,dis-split-quirk"); + dwc->gctl_reset_quirk = device_property_read_bool(dev, + "snps,gctl-reset-quirk"); dwc->lpm_nyet_threshold = lpm_nyet_threshold; dwc->tx_de_emphasis = tx_de_emphasis; diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index 74323b10a64a..993f243aedc8 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -1252,6 +1252,7 @@ struct dwc3 { unsigned dis_metastability_quirk:1; unsigned dis_split_quirk:1; + unsigned gctl_reset_quirk:1; u16 imod_interval; };