SBC-MediaGX map driver implementation (was 'CFI Devices in x8 mode')

[Alex Lennon]

>>The issue now is that as soon as I access an MTD device (say 'cat
>>/dev/mtd0') my system locks. I have an access LED on the flash
>>which isn't pulsing so I don't think I'm getting as far as actually
talking
>>to the flash over the ISA bus.

>>At the moment I can see I'm OK up to MTD_READ - cfi_intelext_read() ?
>>- and I'll continue tracing through.

I've been using a standard 2.4.2 kernel from ftp.kernel.org.
I made miminal changes - experimental code, processor type to 586,
ran MTD patch script and setup MTD/JFFS as per HOW-TO

This meant the initial kernel was SMP enabled. I traced through to
cfi_cmdset_0001::do_read_onechip() and the kernel is locking at
the first call to spin_lock_bh(chip->mutex).

This call seems a little strange as chip->mutex is implemented
as a pointer to the _spinlock mutex (flashchip.h)

Also there seem to be two wrapper functions, cfi_spin_lock() and
cfi_spin_unlock() which *do* take a pointer to a spinlock_t. (?)

Anyway - I recompiled the kernel without SMP and read access to
/dev/mtd0 works just fine.

I can't imagine an embedded environment requiring SMP (!) but I
mention it just in case there is any concern over the spin locks.

Alex





To unsubscribe, send "unsubscribe mtd" to majordomo at infradead.org