From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Date: Tue, 05 Oct 2004 20:51:02 +0000 Subject: Re: finally solve the bad sysfs-timing for all of us Message-Id: <20041005205102.GA5083@kroah.com> List-Id: References: <20040921171734.GA7778@vrfy.org> In-Reply-To: <20040921171734.GA7778@vrfy.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org On Tue, Sep 21, 2004 at 10:04:57PM +0200, Kay Sievers wrote: > On Tue, Sep 21, 2004 at 07:17:34PM +0200, Kay Sievers wrote: > > During the integration of HAL into the linux hotplug system, we dicover > > every week a new signaling path that fails cause of the delayed > > population of the sysfs files, which are connected by symlinks and > > appear in something like a random order in userspace. > > > > It's pretty complicated to understand the connection between all these > > files for all the different subsystems with all the exceptions, so most > > of the users simply sleep a few seconds, but that is not acceptable for > > our integration work. > > > > Here I try to get all the special knowledge about that behavior together > > and place that in a simple binary. That program _must_ run first of all > > other hotplug processsing and every later script, udev or HAL all can get > > rid of the wild guesses about the right time sysfs is ready. > > > > It will not only wait for the "dev"-file events we handle with udev, also > > for every /device-device with the corresponding bus link. > > > > It is provided as a patch against the current udev tree and a "install" will > > place the new program in the hotplug.d directory: > > > > [kay@pim ~]$ tree /etc/hotplug.d/ > > /etc/hotplug.d/ > > `-- default > > |-- 00-wait_for_sysfs.hotplug -> /sbin/wait_for_sysfs > > |-- 10-udev.hotplug -> /sbin/udevsend > > |-- 20-hal.hotplug -> /usr/libexec/hal.hotplug > > |-- default.hotplug > > `-- log.hotplug > > > > > > For now, it logs the result of the waiting to syslog, to catch any > > device, that needs special treatment. All newly discovered delay problems, > > device black/whitelist updates should go into that program and we may remove > > that kind of specialisation from all the other hotplug programs. > > > > Any patches, reports, testing is more than welcome. > > > > Sample debug: > > Sep 21 18:44:07 localhost kernel: usb 3-2: new full speed USB device using address 12 > > Sep 21 18:44:07 localhost kernel: hub 3-2:1.0: USB hub found > > Sep 21 18:44:07 localhost kernel: hub 3-2:1.0: 2 ports detected > > Sep 21 18:44:07 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2' > > Sep 21 18:44:07 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0' > > Sep 21 18:44:08 localhost kernel: usb 3-2.1: new full speed USB device using address 13 > > Sep 21 18:44:08 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/class/usb/lp0' > > Sep 21 18:44:08 localhost kernel: drivers/usb/class/usblp.c: usblp0: USB Bidirectional printer dev 13 if 0 alt 1 proto 2 vid 0x067B pid 0x2305 > > Sep 21 18:44:08 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.1/3-2.1:1.0' > > Sep 21 18:44:08 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.1' > > Sep 21 18:44:08 localhost udev: configured rule in '/etc/udev/rules.d/50-udev.rules' at line 29 applied, 'lp0' becomes 'usb/%k' > > Sep 21 18:44:08 localhost udev: creating device node '/udev/usb/lp0' > > Sep 21 18:44:09 localhost kernel: usb 3-2.2: new full speed USB device using address 14 > > Sep 21 18:44:09 localhost kernel: pl2303 3-2.2:1.0: PL-2303 converter detected > > Sep 21 18:44:09 localhost kernel: usb 3-2.2: PL-2303 converter now attached to ttyUSB0 > > Sep 21 18:44:09 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.2' > > Sep 21 18:44:09 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.2/3-2.2:1.0' > > Sep 21 18:44:09 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2.2/3-2.2:1.0/ttyUSB0' > > Sep 21 18:44:09 localhost 00-wait_for_sysfs.hotplug: result: waiting for sysfs successful '/class/tty/ttyUSB0' > > Sep 21 18:44:09 localhost udev: creating device node '/udev/ttyUSB0' > > New version with more devices excluded from /device-link saerch and > a better maching for device names. Applied, thanks. greg k-h ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel