On Fri, Jan 18, 2019 at 08:15:02PM +0000, Måns Rullgård wrote: > Bin Liu <b-liu@xxxxxx> writes: > > > On Mon, Dec 17, 2018 at 09:36:17PM +0000, Måns Rullgård wrote: > >> Bin Liu <b-liu@xxxxxx> writes: > >> > >> > On Mon, Dec 17, 2018 at 07:16:08PM +0000, Måns Rullgård wrote: > >> >> Bin Liu <b-liu@xxxxxx> writes: > >> >> > >> >> > Hi, > >> >> > > >> >> > On Mon, Dec 17, 2018 at 03:13:12PM +0000, Måns Rullgård wrote: > >> >> >> I have a strange problem with the musb driver in host mode on AM3358 > >> >> >> (beaglebone) hardware. If I connect a multi-port serial adapter and Is this on beaglebone or beagleboneblack? > >> >> >> open two or more of the ttys, then unplug the device, an interrupt storm > >> >> >> ensues that makes the system completely unresponsive until the watchdog > >> >> >> resets it. Enabling some debug messages, I get this repeated endlessly: > >> >> >> > >> >> >> musb-hdrc musb-hdrc.1: usbintr (0) epintr(1c0000) > >> >> >> musb-hdrc musb-hdrc.1: end 2 RX proto error > >> >> >> musb-hdrc musb-hdrc.1: ... next ep2 RX urb 72aabc13 > >> >> >> musb-hdrc musb-hdrc.1: <-- hw2 urb 72aabc13 spd3 dev4 ep3in h_addr02 h_port00 bytes 4096 > >> >> >> musb-hdrc musb-hdrc.1: RXCSR2 := 2020 > >> >> >> musb-hdrc musb-hdrc.1: end 3 RX proto error > >> >> >> musb-hdrc musb-hdrc.1: ... next ep3 RX urb 94c2cc43 > >> >> >> musb-hdrc musb-hdrc.1: <-- hw3 urb 94c2cc43 spd3 dev4 ep2in h_addr02 h_port00 bytes 4096 > >> >> >> musb-hdrc musb-hdrc.1: RXCSR3 := 2020 > >> >> >> musb-hdrc musb-hdrc.1: end 4 RX proto error > >> >> >> musb-hdrc musb-hdrc.1: ... next ep4 RX urb cbdc39c6 > >> >> >> musb-hdrc musb-hdrc.1: <-- hw4 urb cbdc39c6 spd3 dev4 ep5in h_addr02 h_port00 bytes 4096 > >> >> >> musb-hdrc musb-hdrc.1: RXCSR4 := 2020 > >> >> >> > >> >> >> This happens with both a two-port FTDI serial adapter and a Simcom GSM > >> >> >> modem (Qualcomm based) using the "option" driver. In both cases, the > >> >> >> problem occurs only if two or more of the ttys are opened when the > >> >> >> device is unplugged. > >> >> > > >> >> > Please help me to understand the test case so that I can try to > >> >> > replicate the issue - if I connect a multi-port FTDI adapter, use cat > >> >> > command to open more than one port then unplug the adapter, I should > >> >> > see the flooding debug messages? > >> >> > >> >> Yes, that's what I'm seeing. Obviously, you have to first enable those > >> >> debug messages. Otherwise it just stops dead in its tracks. > >> >> > >> >> I forgot to mention, I also tried making the interrupt handler threaded. > >> >> This allows the system to remain slightly responsive, but it never > >> >> recovers. > >> >> > >> >> > On which kernel version do you see the problem? > >> >> > >> >> This was on 4.19.9. I don't see any later commits that look related, > >> >> but I can try some other tree if you suggest one. > >> > > >> > This should be fine. The driver was barely touched recently. > >> > I have only a few days left for 2018, let me try to reproduce it first > >> > after I am back in Jan. > >> > >> No problem. I suspect most of us will have some time off during the > >> holidays. > >> > >> If it helps, we first noticed this with a 4.9 (stable) kernel, so it's > >> not a recent regression. > > > > When I tried to reproduce the issue today, something weird happened, the > > v4.19.9 kernel I compiled doesn't bring usb1 port on my BBB to host > > mode, otg state was stuck in a_idle, DevCtl register is 0x81. The latest I fixed the the bug which was in the am335x phy driver last week, > > v5.0-rc1 and somewhere in v4.16 do not have such problem. I tried git > > bisect, but it was screwed up somewhere need to start over. I will find > > some time for this issue. > > > > By the way, I don't see the interrupt storm issue with v5.0-rc1 on my > > BBB, when unplugged the FTDI 4-port device, the 'proto error' message > > only shows once for each port opened, then MUSB_DISCONNECT interrupt > > (0x20) happened and everything was torn down. > > I tested this with v5.0-rc2. Now the badness doesn't happen every time, > but two or three attempts is still enough to reproduce it. Also, when > it does happen, the system no longer freezes completely. It is now > possible to interrupt the process with the tty open, at which point the > kernel prints these messages: > > ftdi_sio ttyUSB0: failed to get modem status: -71 > ftdi_sio ttyUSB0: error from flowcontrol urb > > Meanwhile, about 10k interrupts per second have been recorded. The USB > device is still reported as connected, and the port remains unusable. but I still cannot see the interrupt storm problem in v4.19.9. Did you build the kernel with omap2plus_defconfig without any other changes? Regards, -Bin.
