Legacy i386 system with Intel 440BX chip set: ------------------------------------------------------------------------ # lspci 00:00.0 Host bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (rev 02) 00:01.0 PCI bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX AGP bridge (rev 02) 00:07.0 ISA bridge: Intel Corporation 82371AB/EB/MB PIIX4 ISA (rev 02) 00:07.1 IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01) 00:07.2 USB Controller: Intel Corporation 82371AB/EB/MB PIIX4 USB (rev 01) 00:07.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 02) 00:08.0 SCSI storage controller: Adaptec AHA-2940U/UW/D / AIC-7881U (rev 01) 00:0a.0 Ethernet controller: Lite-On Communications Inc LNE100TX (rev 20) 01:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200 AGP (rev 01) ---------------------------------------------------------------------- Moving from 2.6.23.14 to 2.6.24, the /dev/ttyS* are incorrectly created:- In /var/log/messages:- ---------------------------------------------------------------------- Feb 4 17:01:54 conquest3 kernel: serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A Feb 4 17:01:54 conquest3 kernel: serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A Feb 4 17:01:54 conquest3 kernel: 00:0c: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A Feb 4 17:01:54 conquest3 kernel: 00:0f: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A ------------------------------------------------------------------------ [which is correct.] However:- # ls -l /sys/devices/platform/serial8250/tty/ total 0 drwxr-xr-x 3 root root 0 Feb 8 18:22 ttyS2 drwxr-xr-x 3 root root 0 Feb 8 18:22 ttyS3 [which is incorrect.] udev then creates the wrong devices:- # ls -l /dev/ttyS* crw-rw---- 1 root dialout 4, 66 Feb 8 18:03 /dev/ttyS2 crw-rw---- 1 root dialout 4, 67 Feb 8 18:03 /dev/ttyS3 Accessing those nodes gives errors: # statserial /dev/ttyS3 statserial: TIOCMGET failed: Input/output error Complications: -------------- 1) This is non deterministic: very rarely all four devices appear: ttyS0,ttyS1, ttyS2 and ttyS3. Accessing ttyS0 and ttys1 then works correctly. 2) 2.6.23.14 (and probably earlier kernels) also generated 4 devices, and rarely had a similar problem - but I can't recall exact details. Thus the bug might have been around for a longish period with some sort of race triggered almost always in 2.6.24. ------------------------------------------------------------------------- Anyone throw any light on this? ael - 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
