fpga is our own driver. The driver does call misc_register at the beginning of it's init call. It seems that this routine should create the /sys/class/misc/fpga entry. The odd thing is that there is a /sys/module/fpga entry, just not the /sys/class/misc/fpga entry. Also a cat of /proc/modules shows the driver as loaded. I'll trace through the misc_register function a bit and see if there's something strange going on. Keep in mind, that when kgdb is not configured, things work fine. It's only when kgdb is configured that the device node doesn't appear. Rich -----Original Message----- From: Kay Sievers [mailto:kay.sievers@xxxxxxxx] Sent: Wed 1/28/2009 9:00 AM To: Richard Schmitt Cc: linux-hotplug@xxxxxxxxxxxxxxx Subject: Re: Odd behavior with udev and kgdb On Wed, Jan 28, 2009 at 14:31, Richard Schmitt <rschmitt@xxxxxxxxxxx> wrote: > > I'm analyzing a problem where when KGDB is compiled for the kernel, the device node for one of our drivers does not appear. If we unconfigure KGDB, the device node appears fine. > > It's completely reproducible. No other changes to the config file. The config file settings for KGDB are: > > CONFIG_KGDB=y > CONFIG_KGDBOC=y > CONFIG_KGDBOC_NOMODULE=y > CONFIG_KGDB_CONSOLE=y > CONFIG_SERIAL_POLL=y > > I'm wondering if it's a udev problem or something else. > > I have noticed that when KGDB is not configured and the device node is created, there is an entry at: > /sys/class/misc/fpga > > When KGBD is configured, there is no such entry in sysfs. Does this entry get created after udev does it's thing, or is udev dependent on the sysfs entry being created? > > If udev is dependent on the sysfs entry, does anyone have any idea why this entry would not get created, but only if KGDB is configured? Udev creates stuff only after it has shown up in /sys. If there is no /sys device, there is no udev action. The /sys devices are created when a kernel driver/module requests them, udev can not create anything in /sys. What driver/module is/creates "fpga"? Is that in the upstream kernel? Kay -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
