cfi_cmdset_0001 get_chip()put_chip() contender/loaner, what does it do?

[Nicolas Pitre]

On Tue, 12 Jun 2007, Joakim Tjernlund wrote:

> In the beginning of get_chip() and put_chip for the cfi_cmdset_0001
> driver there is this "fight" over access to the chip that I don't
> understand. Why is it there and why don't the other drivers need it?

It is there to support the Intel Sibley NOR flash chips which have the 
ability to allow read operations in many part of the chip at the same 
time as an erase or a write operation taking place in another part of 
the chip.  The erase and write operation, though, cannot have more than 
one instance on the whole chip.

To facilitate the driver implementation, the Sibley flash is subdivided 
in many "chips" corresponding to those parts mentioned above.  However, 
since the ability to write is shared amongst all those "chips" then it 
sometimes must be obtained from another chip.  The other chip might 
concede it or it might not.  That's the "fighting".

> This construct has been there for a long time and git blame does not
> tell me the author of this code.

It was me.


Nicolas