Re: vme_tsi148 question

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On 28/12/13 00:34, Michael Kenney wrote:
Hi Martyn,

On Fri, Dec 27, 2013 at 4:23 PM, Martyn Welch <martyn@xxxxxxxxxxxx> wrote:
On 27/12/13 20:15, Michael Kenney wrote:

We are using the vme_tsi148 bridge driver along with the vme_user
driver to access the VME boards. The A/D board requires D32 bus cycles
and the VME master window is configured accordingly, however, when
monitoring the bus cycles with a logic analyzer, we noticed that the
CPU is transferring one byte at a time (i.e. four D8 transfers rather
than one D32).

Is this the expected behavior of the tsi148 driver?


Hi Mike,

This is certainly not the expected behaviour - if the window is configured
for D32 then it should do 32 bit transfers where possible.

I've heard of this happening recently, but haven't yet been able to
replicate it. Which VME board are you running Linux on and which flavour of
Linux?

I'm running Debian 7.2 with kernel 3.2 on a Fastwel CPC600 (Pentium M
based CPU board).


I haven't forgotten about this, still not sure exactly what is happening.

Is your install/kernel 32 or 64 bit?

Are you doing single 32-bit transfers, or are you seeing this on longer transfers (i.e. copying a buffer full of data)?

Martyn

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