On (28/01/13 13:09), [email protected] wrote: > > _______________________________________ > > From: Darren Hart [[email protected]] > > Sent: Monday, January 28, 2013 12:52 PM > > To: Brown, Michael E > > Cc: [email protected] > > Subject: Re: [OE-core] udev blacklist ineffective > > > > On 01/28/2013 08:36 AM, [email protected] wrote: > > > I have two embedded systems that share some devices over an i2c bus. Only > > > one system may load the device driver at a time, and loading the device > > > driver is already well-controlled by the HA subsystem. > > > > > > Our new yocto build with udev enabled is auto-loading these device > > > drivers with catastrophic results. We must absolutely prohibit such > > > automatic behaviour for our list of devices. I have tried: > > > > > > $ cat etc/modprobe.d/blacklist.conf > > > blacklist seepmtd > > > ... cut ... > > > > > > And this does *NOT* work. I have tried renaming blacklist.conf to > > > modprobe.conf as well as creating modprobe.conf with these blacklist > > > entries. > > > > > > This is a huge blocking issue and I have been unable to figure out a > > > workaround for it. I would appreciate any suggestions. > > > > > > OK, so... this needs to be addressed. > > > > However, can you just not build/install the drivers for the system that > > shouldn't be accessing them? Or do you require a more general image? > > Both systems have to access these devices. They just cannot load the drivers > simultaneously. The driver load is under control of the HA process that > ensures that only one system at a time accesses the devices, and takes care > of fencing, etc. > > We have a custom FPGA that can switch access to the devices between two > systems, loading drivers from both systems twiddles bits that ought not to be > twiddled and catastrophically crashes one or both systems. > > > You will need to provide details about the version of oe-core you are > > using, kmod or modutils, and any relevant DISTRO configurations you have > > made, which bit of software do you expect to be honoring the blacklist, etc. > > Yocto release 1.3, danny branch + meta-oe/meta-systemd for system startup > udev_v195-r10 > libkmod2_9-r0.0 > > Distro is poky + systemd > > What is happening is that, on boot, the udev Coldplug startup step is loading > drivers that must not be loaded based on i2c discovery.
yes udev is exactly for that. You are up for writing some udev rules here may be something etc/udev/rules.d/10-local.rules and add OPTIONS=="ignore_device" if condition (that you will define based on device you want to ignore) is met. > -- > Michael > > _______________________________________________ > Openembedded-core mailing list > [email protected] > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core -- -Khem _______________________________________________ Openembedded-core mailing list [email protected] http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core
