Re: [patch 6/7] SDHCI: Check DMA for overruns at end of transfer

From: Ben Dooks
Date: Mon Nov 03 2008 - 16:16:37 EST


On Mon, Nov 03, 2008 at 07:12:00PM -0200, Henrique de Moraes Holschuh wrote:
> Maybe I didn't understand it right, but if the DMA controller could overrun
> a buffer, don't you ALSO need to add defensive padding (i.e. increase the
> buffer) to make sure nothing important gets overrun?

This is only generated by problems elsewhere in the driver, such as
getting the timeout clock wrong. It is here just as a precaution and
as an aide to debugging, it should not trigger in normal circumstances.

There is a seperate problem where the DMA buffer is passed from the stack
which is, IIRC, a complete no-no under Linux.

--
Ben

Q: What's a light-year?
A: One-third less calories than a regular year.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/