Subject: Re: [PATCH 2/2] [POWERPC] mmio ide support for mpc8349-itx target

From: Arnd Bergmann <[email-masked]>
Date: Sat, 7 Jul 2007 17:12:44 +0200

On Saturday 07 July 2007, Olof Johansson wrote:
> On Sat, Jul 07, 2007 at 01:49:00PM +0400, Vitaly Bordug wrote:
> > 
> > This updates relevant platform code
> > (freescale mpc8349itx target) to make the CompactFlash
> > work in TrueIDE mode.
> 
> Shouldn't you be writing a PCMCIA driver instead for the CF, so it
> handles other devices as well? Then you get storage "for free", as
> well as hotplug, etc.

CF memory cards can be in either TrueIDE mode or PCMCIA mode. If you
only need to support memory cards, you should always use True-IDE
mode, because that offers a _much_ higher throughput with PIO mode
6 (25 MB/s) or UDMA mode 6 (133MB/s), compared to the PIO mode 0
(3.3 MB/s) in PCMCIA mode.

Of course, if the bus can only sustain PIO mode 0 anyway, you can
just as well do a PCMCIA driver, and get the ability to plug in
other cards, e.g. wlan or modem cards.

	Arnd <><