On Sun, Apr 14, 2013 at 09:53:57AM -0500, Timur Tabi wrote: > Markus Pargmann wrote: > >In general, imx27 does support SSI with DMA, for example > >MACH_IMX27_VISSTRIM_M10 does use SSI with DMA. But there are special > >boards like Eukrea TLV320 and phycore-ac97 that have to use FIQ instead. > >All of them have a imx27 chip. > > Why is the decision to use FIQ board-specific? All of the hardware > is inside the SoC itself. How could a board make using DMA > impossible?
I only ported the imx-ssi ac97 driver code and tested twice using DMA without success. But there is a good description of the problem in imx-ssi: " The WM9712 with which this driver was developed with always sends GPIO status data in slot 12 which we receive in our (PCM-) data stream. The only chance we have is to manually skip this data in the FIQ handler." Regards, Markus -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
