> -----Original Message----- > From: Linyu Yuan [mailto:quic_linyyuan@xxxxxxxxxxx] > 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. 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@xxxxxxxxxxx> > >> --- > >> 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; > >
