[PATCH] mtd: spi-nor: fix the wrong dummy value

Marek Vasut marex at denx.de
Thu Apr 17 04:32:52 PDT 2014


On Thursday, April 17, 2014 at 07:01:25 AM, Huang Shijie wrote:
> On Thu, Apr 17, 2014 at 01:40:29AM +0200, Marek Vasut wrote:
> > On Wednesday, April 16, 2014 at 10:18:19 AM, Huang Shijie wrote:
> > > The dummy cycles is actually 8 for SPI fast/dual/quad read.
> > > 
> > > This patch fixes the wrong dummy value for both the spi-nor.c and
> > > m25p80.c.
> > > 
> > > Signed-off-by: Huang Shijie <b32955 at freescale.com>
> > 
> > Inspecting this patch, I see the code will behave identically
> > with/without this patch. It is thus unclear to me from the commit
> > message, why this change is necessary.
> 
> firstly, in theory, the dummy cycles should be 8, not 1.
> secondly, the DDR QUAD READ may use 4 dummy cycles.

Right, it took me a bit of reading into the thread until I understood the 
intention of the patch. If in doubt, try reading the commit message a day
later and you'll see that it might be insufficient. Basically, try looking
at the commit message from the receiving party's side ;-)

Best regards,
Marek Vasut



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