From: marex@denx.de (Marek Vasut)
Date: Thu, 1 Nov 2012 15:28:17 +0100
Subject: [PATCH] i2c: mxs: remove broken PIOQUEUE support
In-Reply-To: <1351771003-6071-1-git-send-email-w.sang@pengutronix.de>
References: <1351771003-6071-1-git-send-email-w.sang@pengutronix.de>
Message-ID: <201211011528.17596.marex@denx.de>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Dear Wolfram Sang,

> This I2C master can do DMA and PIOQUEUE (PIO with FIFO). Originally,
> only PIOQEUE

PIOQUEUE ;-)

> was supported, then DMA support was added. The original
> intention was to keep PIOQUEUE since it has less overhead what is nice
> for small transfers. However, runtime switching between PIOQEUE and DMA
> depending on the transfer size never worked despite a lot of trying.
> Since PIOQUEUE mode itself was flaky (polling at places where interrupts
> failed to work) and the implementation also imposed a size limit for
> transfers, it is best to remove the support altogether which makes the
> driver a lot cleaner and more robust. If somebody really wants less
> overhead, plain PIO mode could still be implemented with the addidtional
> advantage that this mode is also available on MX23, too.

Yes, looks to be the way to go.

Reviewed-by: Marek Vasut <marex@denx.de>

Thanks

[...]

Best regards,
Marek Vasut