On Wed, Mar 30, 2016 at 08:30:34AM -0400, Christopher Covington wrote: > Hi Greg, > > On 03/15/2016 06:08 AM, Andre Przywara wrote: > > Hi Christopher, > > > > On 11/03/16 06:35, Christopher Covington wrote: > >> Version 2 of the Server Base System Architecture (SBSAv2) describes the > >> Generic UART registers as 32 bits wide. At least one implementation, found > >> on the Qualcomm Technologies QDF2432, only supports 32 bit accesses. > >> SBSAv3, which describes supported access sizes in greater detail, > >> explicitly requires support for both 16 and 32 bit accesses to all > >> registers (and 8 bit accesses to some but not all). Therefore, for broad > >> compatibility, simply use 32 bit accessors for the SBSA UART. > >> > >> Tested-by: Mark Langsdorf <[email protected]> > >> Signed-off-by: Christopher Covington <[email protected]> > > > > So I gave this a try on a Juno and a Midway. Both have a normal PL011, > > but I changed the DT to advertise an SBSA UART instead. > > This worked fine with the 32bit accessors. > > Also according to some research on the hardware size at least the > > current ARM PL011 implementation are totally fine with 32-bit (as well > > as 16-bit) accesses. > > There is some reluctance about whether this is true for _every_ older > > PL011 implementation, but they are out of scope here, as we are talking > > about the SBSA only. > > So: > > > > Tested-by: Andre Przywara <[email protected]> > > Acked-by: Andre Przywara <[email protected]> > > > > You can add Juno and Midway to the list of tested systems. > > >> Changes new in v2: > > Apologies for omitting the v2 prefix in the second version of the patch > that I sent out. > > >> * Fixed from address > >> * Elaborated on forward (SBSAv3) compatibility in commit message > >> * Included Mark Langsdorf's Tested-by, which now covers: > >> QDF2432 > >> Seattle > >> X-Gene 1 > > >> --- > >> drivers/tty/serial/amba-pl011.c | 1 + > >> 1 file changed, 1 insertion(+) > >> > >> diff --git a/drivers/tty/serial/amba-pl011.c > >> b/drivers/tty/serial/amba-pl011.c > >> index c0da0cc..ffb5eb8 100644 > >> --- a/drivers/tty/serial/amba-pl011.c > >> +++ b/drivers/tty/serial/amba-pl011.c > >> @@ -121,6 +121,7 @@ static struct vendor_data vendor_arm = { > >> > >> static struct vendor_data vendor_sbsa = { > >> .reg_offset = pl011_std_offsets, > >> + .access_32b = true, > >> .oversampling = false, > >> .dma_threshold = false, > >> .cts_event_workaround = false, > >> > > Do you consider this patch suitable to be included in a 4.6 release > candidate? It fixes an issue running this driver on certain hardware, > and with gracious assistance we've performed due diligence to check that > it does not adversely affect the driver running on other hardware. Would > it be useful to send a v3 collecting the acks and tested-bys?
If this isn't a bug fix or regression fix, it's not ok for 4.6-final, it will have to wait for 4.7-rc1. And yes, collecting the acks and tested-bys would be great, I'm always glad to see that, it makes my job easier. Now that 4.6-rc1 is out, I'll start to dig through the list of pending patches here, give me a few weeks to get all of them, especially due to the conference travel I'm currently doing... thanks, greg k-h
