Re: [PATCH v4 5/9] usb: dwc3: core: make dual-role work with OTG irq

Roger Quadros
2015-09-03T13:52:16Z

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On 02/09/15 17:43, Felipe Balbi wrote:
> Hi,
>
> On Wed, Sep 02, 2015 at 05:24:20PM +0300, Roger Quadros wrote:
>> If the ID pin event is not available over extcon
>> then we rely on the OTG controller to provide us ID and VBUS
>> information.
>>
>> We still don't support any OTG features but just
>> dual-role operation.
>>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> ---
>> drivers/usb/dwc3/core.c | 217 ++++++++++++++++++++++++++++++++++++++++++++----
>> drivers/usb/dwc3/core.h | 3 +
>> 2 files changed, 205 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>> index 38b31df..632ee53 100644
>> --- a/drivers/usb/dwc3/core.c
>> +++ b/drivers/usb/dwc3/core.c
>> @@ -704,6 +704,63 @@ static int dwc3_core_get_phy(struct dwc3 *dwc)
>> return 0;
>> }
>>
>> +/* Get OTG events and sync it to OTG fsm */
>> +static void dwc3_otg_fsm_sync(struct dwc3 *dwc)
>> +{
>> + u32 reg;
>> + int id, vbus;
>> +
>> + reg = dwc3_readl(dwc->regs, DWC3_OSTS);
>> + dev_dbg(dwc->dev, "otgstatus 0x%x\n", reg);
>> +
>> + id = !!(reg & DWC3_OSTS_CONIDSTS);
>> + vbus = !!(reg & DWC3_OSTS_BSESVLD);
>> +
>> + if (id != dwc->fsm->id || vbus != dwc->fsm->b_sess_vld) {
>> + dev_dbg(dwc->dev, "id %d vbus %d\n", id, vbus);
>> + dwc->fsm->id = id;
>> + dwc->fsm->b_sess_vld = vbus;
>> + usb_otg_sync_inputs(dwc->fsm);
>> + }
>
> this guy shouldn't try to filter events here. That's what the FSM should
> be doing.

OK. I'll remove the if condition.

>
>> +}
>> +
>> +static irqreturn_t dwc3_otg_thread_irq(int irq, void *_dwc)
>> +{
>> + struct dwc3 *dwc = _dwc;
>> + unsigned long flags;
>> + irqreturn_t ret = IRQ_NONE;
>
> this IRQ will be disabled pretty quickly. You *always* return IRQ_NONE
>
>> + spin_lock_irqsave(&dwc->lock, flags);
>
> if you cache current OSTS in dwc3, you can use that instead and change
> this to a spin_lock() instead of disabling IRQs here. This device's IRQs
> are already masked anyway.

OK.

>
>> + dwc3_otg_fsm_sync(dwc);
>> + /* unmask interrupts */
>> + dwc3_writel(dwc->regs, DWC3_OEVTEN, dwc->oevten);
>> + spin_unlock_irqrestore(&dwc->lock, flags);
>> +
>> + return ret;
>> +}
>> +
>> +static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)
>> +{
>> + struct dwc3 *dwc = _dwc;
>> + irqreturn_t ret = IRQ_NONE;
>> + u32 reg;
>> +
>> + spin_lock(&dwc->lock);
>
> this seems unnecessary, we're already in hardirq with IRQs disabled.
> What sort of race could we have ? (in fact, this also needs change in
> dwc3/gadget.c).

You're right. Will fix at both places.
>
>> +
>> + reg = dwc3_readl(dwc->regs, DWC3_OEVT);
>> + if (reg) {
>> + dwc3_writel(dwc->regs, DWC3_OEVT, reg);
>> + /* mask interrupts till processed */
>> + dwc->oevten = dwc3_readl(dwc->regs, DWC3_OEVTEN);
>> + dwc3_writel(dwc->regs, DWC3_OEVTEN, 0);
>> + ret = IRQ_WAKE_THREAD;
>> + }
>> +
>> + spin_unlock(&dwc->lock);
>> +
>> + return ret;
>> +}
>> +
>> /* --------------------- Dual-Role management ------------------------------- */
>>
>> static void dwc3_drd_fsm_sync(struct dwc3 *dwc)
>> @@ -728,15 +785,44 @@ static int dwc3_drd_start_host(struct otg_fsm *fsm, int on)
>> {
>> struct device *dev = usb_otg_fsm_to_dev(fsm);
>> struct dwc3 *dwc = dev_get_drvdata(dev);
>> + u32 reg;
>>
>> dev_dbg(dwc->dev, "%s: %d\n", __func__, on);
>> + if (dwc->edev) {
>> + if (on) {
>> + dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_HOST);
>> + /* start the HCD */
>> + usb_otg_start_host(fsm, true);
>> + } else {
>> + /* stop the HCD */
>> + usb_otg_start_host(fsm, false);
>> + }
>
> if (on)
> dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_HOST);
> usb_otg_start_host(fsm, on);
>

OK.

>> +
>> + return 0;
>> + }
>> +
>> + /* switch OTG core */
>> if (on) {
>> - dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_HOST);
>> + /* OCTL.PeriMode = 0 */
>> + reg = dwc3_readl(dwc->regs, DWC3_OCTL);
>> + reg &= ~DWC3_OCTL_PERIMODE;
>> + dwc3_writel(dwc->regs, DWC3_OCTL, reg);
>> + /* unconditionally turn on VBUS */
>> + reg |= DWC3_OCTL_PRTPWRCTL;
>> + dwc3_writel(dwc->regs, DWC3_OCTL, reg);
>> /* start the HCD */
>> usb_otg_start_host(fsm, true);
>> } else {
>> /* stop the HCD */
>> usb_otg_start_host(fsm, false);
>> + /* turn off VBUS */
>> + reg = dwc3_readl(dwc->regs, DWC3_OCTL);
>> + reg &= ~DWC3_OCTL_PRTPWRCTL;
>> + dwc3_writel(dwc->regs, DWC3_OCTL, reg);
>> + /* OCTL.PeriMode = 1 */
>> + reg = dwc3_readl(dwc->regs, DWC3_OCTL);
>> + reg |= DWC3_OCTL_PERIMODE;
>> + dwc3_writel(dwc->regs, DWC3_OCTL, reg);
>> }
>
> it looks like you're not really following the fluxchart from SNPS
> documentation, see Figure 11-4 on section 11.1.4.5

Did you mean that I'm ignoring all OTG bits (HNP/SRP/ADP)?

>
>> @@ -746,15 +832,48 @@ static int dwc3_drd_start_gadget(struct otg_fsm *fsm, int on)
>> {
>> struct device *dev = usb_otg_fsm_to_dev(fsm);
>> struct dwc3 *dwc = dev_get_drvdata(dev);
>> + u32 reg;
>>
>> dev_dbg(dwc->dev, "%s: %d\n", __func__, on);
>> - if (on) {
>> - dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
>> + if (on)
>> dwc3_event_buffers_setup(dwc);
>>
>> + if (dwc->edev) {
>> + if (on) {
>> + dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
>> + usb_otg_start_gadget(fsm, true);
>> + } else {
>> + usb_otg_start_gadget(fsm, false);
>> + }
>> +
>> + return 0;
>> + }
>> +
>> + /* switch OTG core */
>> + if (on) {
>> + /* OCTL.PeriMode = 1 */
>> + reg = dwc3_readl(dwc->regs, DWC3_OCTL);
>> + reg |= DWC3_OCTL_PERIMODE;
>> + dwc3_writel(dwc->regs, DWC3_OCTL, reg);
>> + /* GUSB2PHYCFG0.SusPHY = 1 */
>> + if (!dwc->dis_u2_susphy_quirk) {
>> + reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
>> + reg |= DWC3_GUSB2PHYCFG_SUSPHY;
>> + dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
>> + }
>> /* start the UDC */
>> usb_otg_start_gadget(fsm, true);
>> } else {
>> + /* GUSB2PHYCFG0.SusPHY=0 */
>> + if (!dwc->dis_u2_susphy_quirk) {
>> + reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
>> + reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
>> + dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
>> + }
>> + /* OCTL.PeriMode = 1 */
>> + reg = dwc3_readl(dwc->regs, DWC3_OCTL);
>> + reg |= DWC3_OCTL_PERIMODE;
>> + dwc3_writel(dwc->regs, DWC3_OCTL, reg);
>> /* stop the UDC */
>> usb_otg_start_gadget(fsm, false);
>> }
>> @@ -777,10 +896,30 @@ static int dwc3_drd_notifier(struct notifier_block *nb,
>> return NOTIFY_DONE;
>> }
>>

- --
cheers,
- -roger
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