From: Alex Buell <alex.buell@xxxxxxxxxxxxx> Date: Tue, 04 Jan 2011 20:11:17 +0000 > I'm already doing that. In the instances where it results in a crash and > reboots are impossible, dropping into the OpenPROM results in a total > system freeze, cannot type anything in, this means a big red switch > time. Solaris didn't have this problem. Any ideas why Linux does this to > the OpenPROM? First of all, the machine dies because those illegal I/O accesses generate an unrecoverable asynchronous memory error, we cannot recover from it so we have to panic the entire machine. Secondly, the keyboard doesn't work because I never implemented the monstrous amount of code necessary to allow USB keyboard to work with OpenPROM after booting up. You have to essentially reset the entire USB host controller, unload all of the pending queued URBs in the host controller, put it into a quiescent state, and then asynchronously process all USB keyboard device events via USB host controller polling implemented via OpenPROM backcalls into the kernel, and from there feed the characters to OpenPROM so it can see the keypresses. Upon return from OpenPROM you have to reload all of the unloaded URBs back onto the USB host controller queues so the kernel can use USB again. I never considered this enormous amount of work worth doing, the payback is just too small. -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
