2016-04-18 9:55 GMT+03:00 Jiri Slaby <jslaby@xxxxxxx>: > On 04/17/2016, 02:33 PM, Matwey V. Kornilov wrote: >> Hello, >> >> When running 4.6-rc3 (please find used config attached) on BeagleBone Black with 8250_omap serial driver I see the following hung. >> >> When test application a.out run twice (test.c source code attached here) the following happens: >> >> # ./a.out # ./a.out >> (hung here, may be interrupted with Ctrl-C) >> >> Trace from echo t > /proc/sysrq-trigger is the following: >> >> апр 17 12:29:23 nohostname kernel: a.out S c0c3544c 0 922 882 0x00000000 >> апр 17 12:29:23 nohostname kernel: [<c0c3544c>] (__schedule) from [<c0c3597c>] (schedule+0x5c/0xd0) >> апр 17 12:29:23 nohostname kernel: [<c0c3597c>] (schedule) from [<c0794820>] (tty_port_block_til_ready+0x11c/0x2a0) >> апр 17 12:29:23 nohostname kernel: [<c0794820>] (tty_port_block_til_ready) from [<c07abfb0>] (uart_open+0x11c/0x158) > ... >> >> I don't think that open() user-space call should be blocked under such circumstances, so I think that this is rather an issue within the kernel. >> I've found that the effect dissapears when termios calls are dropped from test.c > > I suppose the memset in the program cleared CLOCAL and the subsequent > open waits for carrier... > The same program doesn't hang when fdti_sio based /dev/ttyUSB is being used. > thanks, > -- > js > suse labs > -- With best regards, Matwey V. Kornilov. Sternberg Astronomical Institute, Lomonosov Moscow State University, Russia 119991, Moscow, Universitetsky pr-k 13, +7 (495) 9392382 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
