Messages in this thread | | | Date | Fri, 6 Jan 2023 11:13:07 +0800 | Subject | Re: [PATCH] usb: dwc3: Clear DWC3_EVENT_PENDING when count is 0 | From | Linyu Yuan <> |
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On 1/5/2023 5:54 PM, 정재훈 wrote: > >> -----Original Message----- >> From: Linyu Yuan [mailto:quic_linyyuan@quicinc.com] >> Sent: Thursday, January 5, 2023 12:35 PM >> To: JaeHun Jung; Felipe Balbi; Greg Kroah-Hartman; Thinh Nguyen >> Cc: open list:USB XHCI DRIVER; open list; Seungchull Suh; Daehwan Jung >> Subject: Re: [PATCH] usb: dwc3: Clear DWC3_EVENT_PENDING when count is 0 >> >> >> On 1/5/2023 11:29 AM, Linyu Yuan wrote: >>> On 1/2/2023 1:08 PM, JaeHun Jung wrote: >>>> Sometimes very rarely, The count is 0 and the DWC3 flag is set has >>>> status. >>>> It must not have these status. Because, It can make happen interrupt >>>> storming status. >>> could you help explain without clear the flag, how interrupt storming >>> happen ? >>> >>> as your change didn't touch any hardware register, i don't know how it >>> fix storming. >>> > H/W interrupts are still occur on IP.
I guess we should fix it from IP layer.
but when checking DWC3_EVENT_PENDING flag, it will auto clear in dwc3 thread irq handler.
there is one possible root cause is it cleared only after irq enabled in dwc3_process_event_buf(),
we should move unmask irq operation at end of this function.
> But. ISR doesn't handle it. Because of this > "if (evt->flags & DWC3_EVENT_PENDING)" > > This is event values. > (struct dwc3_event_buffer *) ev_buf = 0xFFFFFF883DBF1180 = kernel_size_le_lo32+0xFFFFFF883B391180 -> ( > (void *) buf = 0xFFFFFFC00DBDD000 = end+0x337D000 -> , > (void *) cache = 0xFFFFFF8839F54080 = kernel_size_le_lo32+0xFFFFFF88376F4080 -> , > (unsigned int) length = 0x1000, > (unsigned int) lpos = 0x0, > (unsigned int) count = 0x0, > (unsigned int) flags = 0x00100001, > (dma_addr_t) dma = 0x00000008BD7D7000, > > *((struct dwc3_event_type *) 0xFFFFFF8839F54080) = ( > is_devspec = 1, > type = 0, > reserved8_31 = 774) > > *((struct dwc3_event_devt *) 0xFFFFFF8839F54080) = ( > one_bit = 1, > device_event = 0, > type = 6, << DWC3_DEVICE_EVENT_SUSPEND > reserved15_12 = 0, > event_info = 3, > reserved31_25 = 0) > > Occurred interrupts are "DWC3_DEVICE_EVENT_SUSPEND". > If when "count has 0" and DWC3_EVENT_PENDING are set at the same time than > ISR and bottom thread couldn't handle next interrupt. > We guessing connected with "dwc3_gadget_process_pending_events()" function. > But, We could not find reproduce way. > > >>> storming from software layer ? >>> >>>> So, It have to clean up DWC3_EVENT_PENDING flags set when count is 0. >>>> It means "There are no interrupts to handle.". >>>> >>>> (struct dwc3_event_buffer *) ev_buf = 0xFFFFFF883DBF1180 ( >>>> (void *) buf = 0xFFFFFFC00DBDD000 = end+0x337D000, >>>> (void *) cache = 0xFFFFFF8839F54080, >>>> (unsigned int) length = 0x1000, >>>> (unsigned int) lpos = 0x0, >>>> (unsigned int) count = 0x0, >>>> (unsigned int) flags = 0x00000001, >>>> (dma_addr_t) dma = 0x00000008BD7D7000, >>>> (struct dwc3 *) dwc = 0xFFFFFF8839CBC880, >>>> (u64) android_kabi_reserved1 = 0x0), >>>> >>>> (time = 47557628930999, irq = 165, fn = dwc3_interrupt, latency = 0, >>>> en = 1), (time = 47557628931268, irq = 165, fn = dwc3_interrupt, >>>> latency = 0, en = 3), (time = 47557628932383, irq = 165, fn = >>>> dwc3_interrupt, latency = 0, en = 1), (time = 47557628932652, irq = >>>> 165, fn = dwc3_interrupt, latency = 0, en = 3), (time = >>>> 47557628933768, irq = 165, fn = dwc3_interrupt, latency = 0, en = 1), >>>> (time = 47557628934037, irq = 165, fn = dwc3_interrupt, latency = 0, >>>> en = 3), (time = 47557628935152, irq = 165, fn = dwc3_interrupt, >>>> latency = 0, en = 1), (time = 47557628935460, irq = 165, fn = >>>> dwc3_interrupt, latency = 0, en = 3), (time = 47557628936575, irq = >>>> 165, fn = dwc3_interrupt, latency = 0, en = 1), (time = >>>> 47557628936845, irq = 165, fn = dwc3_interrupt, latency = 0, en = 3), >>>> (time = 47557628937960, irq = 165, fn = dwc3_interrupt, latency = 0, >>>> en = 1), (time = 47557628938229, irq = 165, fn = dwc3_interrupt, >>>> latency = 0, en = 3), (time = 47557628939345, irq = 165, fn = >>>> dwc3_interrupt, latency = 0, en = 1), (time = 47557628939652, irq = >>>> 165, fn = dwc3_interrupt, latency = 0, en = 3), (time = >>>> 47557628940768, irq = 165, fn = dwc3_interrupt, latency = 0, en = 1), >>>> (time = 47557628941037, irq = 165, fn = dwc3_interrupt, latency = 0, >>>> en = 3), (time = 47557628942152, irq = 165, fn = dwc3_interrupt, >>>> latency = 0, en = 1), (time = 47557628942422, irq = 165, fn = >>>> dwc3_interrupt, latency = 0, en = 3), (time = 47557628943537, irq = >>>> 165, fn = dwc3_interrupt, latency = 0, en = 1), (time = >>>> 47557628943806, irq = 165, fn = dwc3_interrupt, latency = 0, en = 3), >>>> (time = 47557628944922, irq = 165, fn = dwc3_interrupt, latency = 0, >>>> en = 1), (time = 47557628945229, irq = 165, fn = dwc3_interrupt, >>>> latency = 0, en = 3), (time = 47557628946345, irq = 165, fn = >>>> dwc3_interrupt, latency = 0, en = 1), (time = 47557628946614, irq = >>>> 165, fn = dwc3_interrupt, latency = 0, en = 3), (time = >>>> 47557628947729, irq = 165, fn = dwc3_interrupt, latency = 0, en = 1), >>>> (time = 47557628947999, irq = 165, fn = dwc3_interrupt, latency = 0, >>>> en = 3), >>>> >>>> Signed-off-by: JaeHun Jung <jh0801.jung@samsung.com> >>>> --- >>>> drivers/usb/dwc3/gadget.c | 5 ++++- >>>> 1 file changed, 4 insertions(+), 1 deletion(-) diff --git >>>> a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index >>>> 789976567f9f..5d2d5a9b9915 100644 >>>> --- a/drivers/usb/dwc3/gadget.c >>>> +++ b/drivers/usb/dwc3/gadget.c >>>> @@ -4355,8 +4355,11 @@ static irqreturn_t dwc3_check_event_buf(struct >>>> dwc3_event_buffer *evt) >>>> * irq event handler completes before caching new event to >>>> prevent >>>> * losing events. >>>> */ >>>> - if (evt->flags & DWC3_EVENT_PENDING) >>>> + if (evt->flags & DWC3_EVENT_PENDING) { >>>> + if (!evt->count) >>>> + evt->flags &= ~DWC3_EVENT_PENDING; >>>> return IRQ_HANDLED; >>>> + } >>>> count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0)); >>>> count &= DWC3_GEVNTCOUNT_MASK; >>> how about below change ? >>> >>> count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0)); >>> count &= DWC3_GEVNTCOUNT_MASK; >>> - if (!count) >>> + if (!count) { >>> + evt->flags &= ~DWC3_EVENT_PENDING; >>> return IRQ_NONE; >>> + } >> ignore my suggestion, add Thinh to comment. >>> evt->count = count; >>> evt->flags |= DWC3_EVENT_PENDING; >>>
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