Re: Re-entrancy of flash erase/write

[David Woodhouse <dwmw2@infradead.org>]

rob@sysgo.de said:
>  [David, OK to apply this ?] 

I'd rather it was done in the map driver's set_vpp function itself. 
Sometimes you have more than one map driver, because you have different 
regions of flash - but they all share the same Vpp control. In which case 
you need to do the counting in the map driver anyway. 


>  I looked into this a little further: it seems that the erase
> functions in cfi_cmdset_000?.c and amd_flash.c temporarily release the
> chip->mutex while VPP is on. Won't that allow other threads to get
> hold of the mutex and fiddle with VPP, possibly turning it off ? 

I see the possibility, but surely that would only _actually_ happen if we 
started to support writes during erase suspend? Otherwise, the only thing 
that should happen during an erase is a _read_, which doesn't set and clear 
vpp.


--
dwmw2