On Sun, Nov 18, 2012 at 12:47 PM, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > On Sun, Nov 18, 2012 at 12:06:40PM -0500, Josh Coombs wrote: >> Starting with 3.6.5 on a Marvell Kirkwood based GoFlex Net I began >> observing scheduler bugs when using a USB based RTL8712 WiFi NIC. >> These would eventually overwhelm systemd's logger under moderate >> network activity and crash the box. > > Cool, yet another systemd feature :) sysvinit was less hastle... > >> [ 53.173973] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready >> [ 54.191655] BUG: scheduling while atomic: crond/144/0x40000300 >> [ 54.197537] Modules linked in: rmd160 sha1_generic hmac >> blowfish_generic blowfish_common sr_mod cdrom fbcon bitblit softcursor >> font udlfb syscopyarea sysfillrect sysimgblt fb_sys_fops fb >> hid_generic snd_usb_audio snd_usbmidi_lib snd_hwdep mct_u232 >> snd_rawmidi snd_seq_device snd_pcm snd_page_alloc usbhid usbserial >> snd_timer snd hid soundcore mv_cesa cryptodev(O) ipv6 autofs4 >> [ 54.231214] [<c000d020>] (unwind_backtrace+0x0/0xe0) from >> [<c03fd1d0>] (__schedule_bug+0x48/0x60) >> [ 54.240171] [<c03fd1d0>] (__schedule_bug+0x48/0x60) from >> [<c0401258>] (__schedule+0x4c/0x4bc) >> [ 54.248773] [<c0401258>] (__schedule+0x4c/0x4bc) from [<c003b470>] >> (__cond_resched+0x24/0x34) >> [ 54.257365] [<c003b470>] (__cond_resched+0x24/0x34) from >> [<c040175c>] (_cond_resched+0x3c/0x44) >> [ 54.266134] [<c040175c>] (_cond_resched+0x3c/0x44) from >> [<c0010288>] (do_alignment+0x29c/0x784) >> [ 54.274895] [<c0010288>] (do_alignment+0x29c/0x784) from >> [<c00083d8>] (do_DataAbort+0x34/0x98) > > This is actually a known problem... and I have a patch which resolves it > but I've lost track of where things are with that patch through being > distracted by modern platforms... that said, it does seem to be pointing > at a problem which can be sorted in the driver which makes it more > efficient on ARM hardware. > >> diff -ruN a/drivers/staging/rtl8712/rtl871x_sta_mgt.c >> b/drivers/staging/rtl8712/rtl871x_sta_mgt.c >> --- a/drivers/staging/rtl8712/rtl871x_sta_mgt.c 2012-11-05 >> 03:57:06.000000000 -0500 >> +++ b/drivers/staging/rtl8712/rtl871x_sta_mgt.c 2012-11-13 >> 12:54:28.000000000 -0500 >> @@ -55,8 +55,8 @@ >> NUM_STA + 4); >> if (pstapriv->pallocated_stainfo_buf == NULL) >> return _FAIL; >> - pstapriv->pstainfo_buf = pstapriv->pallocated_stainfo_buf + 4 - >> - ((addr_t)(pstapriv->pallocated_stainfo_buf) & 3); >> + pstapriv->pstainfo_buf = pstapriv->pallocated_stainfo_buf + 8 - >> + ((addr_t)(pstapriv->pallocated_stainfo_buf) & 7); > > Are you sure this is safe? Is the allocated buffer large enough for > those additional 4 bytes of alignment you're adding? I'm not certain on that, I bumped the allocations at Andrew's suggestion, but don't know enough to certify the changes as 100% correct. _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
