Re: [PATCH] video: imxfb: correct the bitmask for DMACR_HM/_TM

From: Uwe Kleine-König
Date: Tue Nov 22 2016 - 03:42:22 EST

On Tue, Nov 22, 2016 at 08:54:18AM +0100, Martin Kaiser wrote:
> The HM and TM fields in the LCDC DMA Control Register are 7 bits wide.
> Use the correct mask to allow setting all possible bits.
> Signed-off-by: Martin Kaiser <martin@xxxxxxxxx>
> ---
> This bug was discovered on a board that uses DMACR_TM(16). We ended up
> with TM==0 in the register, the upper three bits were filtered out.
> The LCD DMA Control Register is described in section 33.3.16 of the
> IMX25 reference manual.

For the MX1 which is also supported by this driver, the definitions are
right. So this needs a more sophisticated patch. Also I wonder why the
register definition is in include/linux/platform_data and not in the
driver directly.

Best regards

Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | |