Hi! Am Dienstag, 15. November 2016, 20:13:06 CET schrieb Matwey V. Kornilov: > Hello, > > I am running 4.4.24-4-default from devel:ARM:Factory:Contrib:RaspberryPi3 > > and sometimes see the following when do readings from /sys like > > # cat /sys/devices/system/cpu/cpu?/cpufreq/cpuinfo_cur_freq
Interesting, I haven't seen that error during tests. IceWM polls the current frequency and I also ran cpupower in a loop, so I guess I would've hit it. Is there a reliable way to reproduce it? Just "while true; cat cpuinfo_cur_freq; done" ? > [ 9138.093049] INFO: task cat:4444 blocked for more than 50 seconds. > [ 9138.093058] Not tainted 4.4.24-4-default #1 > [ 9138.093060] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > disables this message. > [ 9138.093073] cat D ffff800000086c28 0 4444 4426 > 0x00000001 > [ 9138.093076] Call trace: > [ 9138.093090] [<ffff800000086c28>] __switch_to+0x90/0xa8 > [ 9138.093097] [<ffff800000749d14>] __schedule+0x234/0x758 > [ 9138.093100] [<ffff80000074a278>] schedule+0x40/0xa0 > [ 9138.093105] [<ffff80000074d25c>] schedule_timeout+0x214/0x280 > [ 9138.093109] [<ffff80000074ae8c>] wait_for_common+0xb4/0x168 > [ 9138.093113] [<ffff80000074af68>] wait_for_completion+0x28/0x38 > [ 9138.093119] [<ffff8000005dd6f0>] rpi_firmware_property_list+0x120/0x280 > [ 9138.093122] [<ffff8000005dd8d0>] rpi_firmware_property+0x80/0xc8 > [ 9138.093133] [<ffff7ffffc115088>] bcm2835_cpufreq_get_clock+0x38/0x88 > [bcm2835_cpufreq] > [ 9138.093138] [<ffff7ffffc1150f4>] bcm2835_cpufreq_get+0x1c/0x28 > [bcm2835_cpufreq] > [ 9138.093144] [<ffff8000005d1264>] __cpufreq_get+0x34/0xc8 > [ 9138.093148] [<ffff8000005d3304>] show_cpuinfo_cur_freq+0x24/0x78 > [ 9138.093151] [<ffff8000005d1208>] show+0x48/0x70 > [ 9138.093157] [<ffff8000002cb990>] sysfs_kf_seq_show+0xc0/0x158 > [ 9138.093161] [<ffff8000002c9f94>] kernfs_seq_show+0x44/0x50 > [ 9138.093166] [<ffff80000026cdac>] seq_read+0x17c/0x438 > [ 9138.093169] [<ffff8000002cac34>] kernfs_fop_read+0x124/0x1b0 > [ 9138.093175] [<ffff800000246430>] __vfs_read+0x48/0xf8 > [ 9138.093178] [<ffff800000246e38>] vfs_read+0x88/0x160 > [ 9138.093182] [<ffff800000247bc4>] SyS_read+0x54/0xb0 > [ 9138.093187] [<ffff800000085e04>] el0_svc_naked+0x38/0x3c > > So, what do you think? Is it known? > Probably I just need to try kernel 4.8.6 from openSUSE:Factory:ARM? I found https://github.com/raspberrypi/linux/issues/1364 , which fits the backtracke by the kernel quite well. You could try different versions of the firmware or even blacklist bcm2835_cpufreq as a workaround. Only the Leap 42.2 kernel has the cpufreq driver, so if you try the TW kernel you will likely not hit this issue. This does mean that the CPU runs at 800 MHz though. Good luck, Fabian -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) -- To unsubscribe, e-mail: [email protected] To contact the owner, e-mail: [email protected]
