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 > 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? On which kernel version do you see the problem? Regards, -Bin.
