On Sat, Dec 3, 2016 at 12:33 PM, Jon Masters <jcm@xxxxxxxxxx> wrote: > Hi Mark, > > On 12/03/2016 12:15 PM, Mark Salter wrote: >> On Sat, 2016-12-03 at 05:06 -0500, Jon Masters wrote: > >>> There is a broader problem with X-Gene SPCR support. The problem is >>> that the 16550 UART in X-Gene requires the 32-bit access quirk (the >>> iotype is set to UPIO_MEM32 for the APMC0D08 device). This means >>> that when univ8250_console_match runs later, it will compare the >>> iotype (MEM32) with the type previously registered with the >>> kernel when the earlycon setup the preferred console. >> >> Linaro has a kernel patch which looks at the bit_width field of the >> port address: >> >> Author: Aleksey Makarov <aleksey.makarov@xxxxxxxxxx> >> Date: Thu Apr 28 19:52:38 2016 +0300 >> >> serial: SPCR: check bit width for the 16550 UART >> >> The SPCR in 3.06.25 firmware has a bit_width field set to 32 and with the >> above patch, I don't need to use console=. But HP firmware on m400 sets >> bit width to 8 so that needs a firmware fix to work with above. Will this patch be posted for upstream? > > Indeed, thanks. Graeme also mentioned that last night. I think this > a good solution for the moment, but still that it makes sense to > have a new 16650 UART type defined in the DBG2 spec for those > requiring 32-bit access (to mirror the type D for pl011). I > heard back from Microsoft this morning that they're looking. Yes, thanks, Jon. It will be nice to have a new 16550 UART type for those requiring 32-bit access. > > Jon. > > -- > Computer Architect | Sent from my Fedora powered laptop > Regards, Duc Dang. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
