Mark Rutland <mark.rutland@xxxxxxx> writes: > On Mon, Oct 03, 2016 at 11:05:53AM +0200, Robert Jarzmik wrote: >> Add a workaround for mainstone, idp and stargate2 boards, for u16 writes >> which must be aligned on 32 bits addresses. >> >> Signed-off-by: Robert Jarzmik <robert.jarzmik@xxxxxxx> >> --- >> Documentation/devicetree/bindings/net/smsc911x.txt | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/net/smsc911x.txt b/Documentation/devicetree/bindings/net/smsc911x.txt >> index 3fed3c124411..224965b7453c 100644 >> --- a/Documentation/devicetree/bindings/net/smsc911x.txt >> +++ b/Documentation/devicetree/bindings/net/smsc911x.txt >> @@ -13,6 +13,8 @@ Optional properties: >> - reg-io-width : Specify the size (in bytes) of the IO accesses that >> should be performed on the device. Valid value for SMSC LAN is >> 2 or 4. If it's omitted or invalid, the size would be 2. >> +- reg-u16-align4 : Boolean, put in place the workaround the force all >> + u16 writes to be 32 bits aligned > > This property name and description is confusing. > > How exactly does this differ from having reg-io-width = <4>, which is > documented immediately above? reg-io-width specifies the IO size, ie. how many data lines are physically connected from the system bus to the lan adapter. reg-u16-align4 tells that a specific hardware doesn't support 16 bit writes not being 32 bits aligned, or said differently that a "store" 16 bits wide on an address of the format 4*n + 2 deserves a special handling in the driver, while a store 16 bits wide on an address of the format 4*n can follow the simple casual case. I'm pretty open to any name you might suggest, these 3 hardwares I know of are really crazy, you can see them in patch 1/3, in the _SMC_outw_align4() function ... Cheers. -- Robert -- 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
