On Thu, Mar 29, 2012 at 2:41 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote: > On Thu, 29 Mar 2012 02:26:34 +0800, Daniel Kurtz <djkurtz at chromium.org> > wrote: >> The GMBUS controller GMBUS3 register is double-buffered. ?Take advantage >> of this ?by writing two 4-byte words before the first wait for HW_RDY. >> This helps keep the GMBUS controller from becoming idle during long writes. >> >> Signed-off-by: Daniel Kurtz <djkurtz at chromium.org> > > "For byte counts that are greater than four bytes, this register will be > written with subsequent data only after the HW_RDY status bit is set" > > Hmm, I had interpretted that as should only be. But if you take into > account that the register is indeed double-buffered, it does make sense > that the hardware itself is only updated after the HW_RDY signal. > Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
In fact, during my experiments using the GMBUS interrupts, the HW_RDY interrupt would only trigger for transactions > 4 bytes after 2 writes to GMBUS3. > -Chris > > -- > Chris Wilson, Intel Open Source Technology Centre
