Currently for PowerPC systems using device tree, the legacy serial ports are allocated in the order by which they are found in the device tree structure. This can cause problems in cases where the device tree nodes are sysnthesized by an external program (kexec for example), which may not preserve the original order of the device tree nodes. This in turn can result in the serial console changing from ttyS0 to ttyS1 unexpectedly. This patch uses the 'cell-index' property (if present) to map UART device tree nodes to legacy serial port number. The cell-index property is widely used in all the Freescale .dts files for PowerPC. Signed-off-by: Curt Brune <curt@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/kernel/legacy_serial.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c index 7b750c4..b717133 100644 --- a/arch/powerpc/kernel/legacy_serial.c +++ b/arch/powerpc/kernel/legacy_serial.c @@ -164,6 +164,8 @@ static int __init add_legacy_soc_port(struct device_node *np, u64 addr; const __be32 *addrp; struct device_node *tsi = of_get_parent(np); + int index = -1, len; + u32 *indexp; /* We only support ports that have a clock frequency properly * encoded in the device-tree. @@ -188,14 +190,19 @@ static int __init add_legacy_soc_port(struct device_node *np, if (addr == OF_BAD_ADDR) return -1; + /* Check if the ports have an ordering, defined by 'cell-index' */ + if (((indexp = (u32*)of_get_property(np, "cell-index", &len)) != NULL) && + (len == sizeof(u32))) + index = *indexp; + /* Add port, irq will be dealt with later. We passed a translated * IO port value. It will be fixed up later along with the irq */ if (tsi && !strcmp(tsi->type, "tsi-bridge")) - return add_legacy_port(np, -1, UPIO_TSI, addr, addr, + return add_legacy_port(np, index, UPIO_TSI, addr, addr, NO_IRQ, legacy_port_flags, 0); else - return add_legacy_port(np, -1, UPIO_MEM, addr, addr, + return add_legacy_port(np, index, UPIO_MEM, addr, addr, NO_IRQ, legacy_port_flags, 0); } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
