On Sun, 5 Aug 2007, Arnd Bergmann wrote: > On Sunday 05 August 2007, Guennadi Liakhovetski wrote: > > I tried using of_serial.c on a (PPC) MPC8241 based system, which has a > > "16650A" compatible double UART built into the SoC. Using of_serial.c > > causes the ports to be autoconfigured, and this fails. The loopback test > > fails, because the MSR register on 824[15] doesn't implement the > > UART_MSR_DCD bit. Question: what's better, teach 8250.c to handle UARTs > > without this bit, or set the UPF_SKIP_TEST bit in of_serial.c for these > > SOCs to skip the loopback test altogether? The latter is certainly easier > > and affects much fewer systems, so, I'd go for that. > > Yes, that sounds good. Just make sure you test the "compatible" property > in the device node for something appropriate. In of_platform_serial_probe(), > you can then do something like > > if (of_device_is_compatible(ofdev, "mpc8241-serial")) > flags |= UPF_SKIP_TEST; That would be a possibility, but that would mean all 8241/8245 have to adjust their .dts. Ok, there are not so many of them in the mainline now (in fact, hardly any apart from linkstation:-)), still. Cannot we use something already available to just check if we're running on such a CPU? Worst case - find and parse cpu node, or maybe using some cpu_feature? Thanks Guennadi --- Guennadi Liakhovetski - 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
