Hi Alan, Em Mon, 8 Jan 2018 14:15:35 -0500 (EST) Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> escreveu: > On Mon, 8 Jan 2018, Linus Torvalds wrote: > > > Can somebody tell which softirq it is that dvb/usb cares about? > > I don't know about the DVB part. The USB part is a little difficult to > analyze, mostly because the bug reports I've seen are mostly from > people running non-vanilla kernels. I suspect that the main reason for people not using non-vanilla Kernels is that, among other bugs, the dwc2 upstream driver has serious troubles handling ISOCH traffic. Using Kernel 4.15-rc7 from this git tree: https://git.linuxtv.org/mchehab/experimental.git/log/?h=softirq_fixup (e. g. with the softirq bug partially reverted with Linux patch, and the DWC2 deferred probe fixed) With a PCTV 461e device, with uses em28xx driver + Montage frontend (with is the same used on dvbsky hardware - except for em28xx). This device doesn't support bulk for DVB, just ISOCH. The drivers work fine on x86. Using a test signal at the bit rate of 56698,4 Kbits/s, that's what happens, when capturing less than one second of data: $ dvbv5-zap -c ~/dvb_channel.conf "tv brasil" -l universal -X 100 -m -t2dvbv5-zap -c ~/dvb_channel.conf "tv brasil" -l universal -X 100 -m -t2 Using LNBf UNIVERSAL Universal, Europe Freqs : 10800 to 11800 MHz, LO: 9750 MHz Freqs : 11600 to 12700 MHz, LO: 10600 MHz using demux 'dvb0.demux0' reading channels from file '/home/mchehab/dvb_channel.conf' tuning to 11468000 Hz (0x00) Signal= -33.90dBm Lock (0x1f) Signal= -33.90dBm C/N= 30.28dB postBER= 2.33x10^-6 dvb_dev_set_bufsize: buffer set to 6160384 dvb_set_pesfilter to 0x2000 354.08s: Starting capture 354.73s: only read 59220 bytes 354.73s: Stopping capture [ 354.000827] dwc2 3f980000.usb: DWC OTG HCD EP DISABLE: bEndpointAddress=0x84, ep->hcpriv=116f41b2 [ 354.000859] dwc2 3f980000.usb: DWC OTG HCD EP RESET: bEndpointAddress=0x84 [ 354.010744] dwc2 3f980000.usb: --Host Channel 5 Interrupt: Frame Overrun-- ... (hundreds of thousands of Frame Overrun messages) [ 354.660857] dwc2 3f980000.usb: --Host Channel 5 Interrupt: Frame Overrun-- [ 354.660935] dwc2 3f980000.usb: DWC OTG HCD URB Dequeue [ 354.660959] dwc2 3f980000.usb: Called usb_hcd_giveback_urb() [ 354.660966] dwc2 3f980000.usb: urb->status = 0 [ 354.660992] dwc2 3f980000.usb: DWC OTG HCD URB Dequeue [ 354.661001] dwc2 3f980000.usb: Called usb_hcd_giveback_urb() [ 354.661008] dwc2 3f980000.usb: urb->status = 0 [ 354.661054] dwc2 3f980000.usb: DWC OTG HCD URB Dequeue [ 354.661065] dwc2 3f980000.usb: Called usb_hcd_giveback_urb() [ 354.661072] dwc2 3f980000.usb: urb->status = 0 [ 354.661107] dwc2 3f980000.usb: DWC OTG HCD URB Dequeue [ 354.661120] dwc2 3f980000.usb: Called usb_hcd_giveback_urb() [ 354.661127] dwc2 3f980000.usb: urb->status = 0 [ 354.661146] dwc2 3f980000.usb: DWC OTG HCD URB Dequeue [ 354.661158] dwc2 3f980000.usb: Called usb_hcd_giveback_urb() [ 354.661165] dwc2 3f980000.usb: urb->status = 0 Kernel was compiled with: CONFIG_USB_DWC2=y CONFIG_USB_DWC2_HOST=y # CONFIG_USB_DWC2_PERIPHERAL is not set # CONFIG_USB_DWC2_DUAL_ROLE is not set # CONFIG_USB_DWC2_PCI is not set CONFIG_USB_DWC2_DEBUG=y # CONFIG_USB_DWC2_VERBOSE is not set # CONFIG_USB_DWC2_TRACK_MISSED_SOFS is not set CONFIG_USB_DWC2_DEBUG_PERIODIC=y As reference, that's the output of lsusb for the PCTV usb hardware: $ lsusb -v -d 2013:0258 Bus 001 Device 005: ID 2013:0258 PCTV Systems Couldn't open device, some information will be missing Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x2013 PCTV Systems idProduct 0x0258 bcdDevice 1.00 iManufacturer 3 iProduct 1 iSerial 2 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 41 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 500mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x84 EP 4 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x0000 1x 0 bytes bInterval 1 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 1 bNumEndpoints 1 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 0 bInterfaceProtocol 0 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x84 EP 4 IN bmAttributes 1 Transfer Type Isochronous Synch Type None Usage Type Data wMaxPacketSize 0x03ac 1x 940 bytes bInterval 1 Cheers, Mauro
