Hi All, We've had a report [1] that the 3.8.4 stable kernel makes a PNP serial port stop working. After testing 3.8.3, the reporter narrowed it down to stable commit eec98f82c637 (tty/8250_pnp: serial port detection regression since v3.7) (upstream commit 77e372a3d82). Reverting that single commit from 3.8.5 allows the serial port to continue working. The machine in question is using an AMI UEFI implementation as the firmware, and on 3.8.3 the serial port has the following in /sys/bus/pnp/devices/00:0a/resources state = active io disabled irq 4 dma disabled With 3.8.[45], the same file has: state = disabled io disabled irq 4 dma disabled In both cases, the io and dma resources are disabled, and an IRQ is assigned. However, the state remains active for the port on 3.8.3. The offending commit mentions this is a BIOS bug from InsydeH2O and that the port is bogus in that case, but we have something similar here with an AMI UEFI implementation (Version: 0406 Release Date: 06/06/2012) where the port isn't bogus. I'm not sure exactly what the solution should be here. Any thoughts? josh [1] https://bugzilla.redhat.com/show_bug.cgi?id=928246 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
