[U-Boot] [PATCH 3/7] eSPI: add eSPI controller support

Mike Frysinger vapier at gentoo.org
Thu Aug 27 08:43:22 CEST 2009


On Thursday 27 August 2009 02:27:30 Hu Mingkai-B21284 wrote:
> > but what if you dont know the length of the transaction ahead
> > of time ?  if you look at the spi flash framework, it'll
> > write a few bytes (like the opcode to read the status
> > register) and then it'll just keep reading 1 byte at a time
> > (polling the status register).  there is no way of knowing
> > the length ahead of time.  most of the SPI code in u-boot
> > operates this way.
>
> So the driver use the length passed by SPI flash read function.
> If the length is greater than the max value that is limited by the
> transaction length register's bitfiled, the driver couldn't read
> anything.

the length used by the first read covers just the length of the opcode, not 
any of the data returned by the part

as long as your driver rejects all of these things, it'll be detected at 
runtime and it should be fine to merge
-mike
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