On 05/21/2013 10:34 AM, Stephen Warren wrote: > On 05/21/2013 12:02 AM, Jongsung Kim wrote: >> Stephen Warren reported the recent commit 78506f2 (add support for >> extended FIFO-size of PL011-r1p5) breaks the serial port on the >> BCM2835 ARM SoC. >> >> A UART compatible with the ARM PL011-r1p5 should have 32-deep FIFOs. >> The BCM2835 UART just looks like an ARM PL011-r1p5, but has 16-deep >> FIFOs just like PL011-r1p4 or earlier revisions. As a workaround for >> this compatibility issue, this patch overrides the HW UART periphid >> register values with the actually compatible UART periphid 0x00241011 >> (r1p3 or r1p4). >> >> Reported-by: Stephen Warren <swarren@xxxxxxxxxxxxx> >> Signed-off-by: Jongsung Kim <neidhard.kim@xxxxxxx> > > I know this will work, because I tried out the same thing last week. > > However, I'm not convinced that it's the correct approach. What other > changes exist between r1p4 and r1p5; can you check in the TRM? Looking at the TRM, it seems this is really the only change, according to the changelog in the documentation (although it's a little difficult to tell since the document seems to have a bunch of changes that presumably don't affect behaviour). So, faking the periphid seems OK. Acked-by: Stephen Warren <swarren@xxxxxxxxxxxxx> Let's apply for 3.10. -- 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
