On Wed, Mar 18, 2009 at 20:44, David Brownell <david-b@xxxxxxxxxxx> wrote: > I have a machine running Debian and it's been getting nasty > boot messages like: > > ... > Synthesizing the initial hotplug events...done. > Waiting for /dev to be fully populated...uncorrectable error : <3>end_request: I/O error, dev mtdblock0, sector 0 > Buffer I/O error on device mtdblock0, logical block 0 > uncorrectable error : <3>end_request: I/O error, dev mtdblock0, sector 8 > Buffer I/O error on device mtdblock0, logical block 1 > end_request: I/O error, dev mtdblock0, sector 16 > Buffer I/O error on device mtdblock0, logical block 2 > end_request: I/O error, dev mtdblock0, sector 24 > Buffer I/O error on device mtdblock0, logical block 3 > uncorrectable error : <3>end_request: I/O error, dev mtdblock0, sector 0 > Buffer I/O error on device mtdblock0, logical block 0 > done. > Setting parameters of disc: (none). > ... > > Where /dev/mtdblock0 is something of a special NAND partition, > used by the mask ROM on the ARM to get a second stage loader, > which is then loaded from /dev/mtdblock1 etc. The messages > about "uncorrectable error" are from the kernel, since that > first partition uses a different ECC scheme than the rest of > the flash. > > What's happening is that it's trying to read partition data > from the MTD devices ... which is inappropriate, they don't > use internal partition data. And the mtdblock0 read fails, > because of the ECC differences, producing messages ... ones > that should never have appeared, since it shouldn't have > been trying to read partition data. > > The boot is easily cleaned up by a patch to a udev rules > file: /etc/udev/rules.d/60-persistent-storage.rules is > already skipping a bunch of devices, it just needs to add > the "mtd*" devices to what should be skipped: > > KERNEL=="ram*|loop*|fd*|mtd*|nbd*|gnbd*|dm-*|md*", GOTO="persistent_storage_end" > > It'd be good to see this bug fixed before lenny goes final... Udev, by default, investigates all block devices which are created by the kernel. People use label/uuid and other metadata based stuff, so we should look at them. We can not know in advance which device will not respond properly. I have requests where people ask for more persistent link support for mtd devices, while disabling them would really not make them happier. :) I don't see how userspace could work around this, and guess the kernel should stop printing errors for stuff it has announced to userspace, but is not usable when we look at it. Would it help, if we make it easier to disable these rules for specific devices from a custom udev rule? Thanks, 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
