Hi Wolfgang,
On Sun, Oct 10, 2010 at 5:22 PM, Wolfgang Denk wd@denx.de wrote:
Dear Lei Wen,
In message AANLkTiny6iZRXoh=Aff1fVPz__B4Sfba1+m+=H97V7ox@mail.gmail.com you wrote:
Please explain why that shouldnot be possible. It's the driver that accesses your hardware, so it has full control over everything going on.
You are right, certainly driver cuold make this, but this would bring a lot of complexity for it... As I mentioned in the last mail, the multi-write command semantic consist by multi-write command + stop transmission command.
Send what kind of command is the job of platform, and how to send the command is the job of driver. If I implement this seperation in the driver level, the driver must send another stop transmission command during each internal seperation, which is so ugly and error prone..
So this is why I intend to put the code in the platform level...
But my (limited!) understanding is that it's not a platform problem you are solving, but one of this special kind of controller, which nobody else would ever run into.
Is this understanding correct?
I think it is a generic problem, and I am also curios why other people don't complain for it... In Linux code, the multi-write write semantic also has such limitation in platform code. So if UBOOT also could have this, that would be so nice...
As you also says that the mmc also server greatly for SD, while the published SD host controller spec has such limitation, I think It is general, right? ...
Best regards, Lei