On Wed, Jan 30, 2013 at 09:32:56AM +0200, Andy Shevchenko wrote: > On Tue, 2013-01-29 at 20:57 +0530, Viresh Kumar wrote: > > On Tue, Jan 29, 2013 at 10:52 AM, Mika Westerberg > > <mika.westerb...@linux.intel.com> wrote: > > > We had a discusssion about this with Andy as well. The thing is that there > > > is no way in current resource to pass DMA request line numbers supported > > > by > > > the controller to the driver in a generic way. We on the other hand have > > > to > > > deal this somehow as we have a shared DMA controller on Lynxpoint where > > > the > > > offset will start from 16 (but it might be something else as well). > > > > > > Is there something which limits the usage of IORESOUCE_DMA to be only > > > usable for ISA DMA channels? > > > > Andy, > > > > Why do we need this request_line_base? Why not program the actual value > > directly into the slave structure (base + offset)? > > Slave device exactly has knowledge about this number slave_id = (base > +offset). However... Btw request line needs to be programmed by client in slave_id field. So why exactly is this required for dma driver?
-- ~Vinod > > In case it is required, add it in platform data field or can add DT > > binding for it. > > We get a device from the ACPI CSRT table. During enumeration we don't > know what kind of the device it is. From the enumeration point of view > each device enumerated from CSRT is a platform device (see > drivers/acpi/csrt.c for the details). > > That's why we have to pass this info somehow to the DMAC driver. And > like Mika already mentioned we have no other generic way except > IORESOURCE_DMA. If you have something better in mind, please share. We > could adopt our code then. > > > -- > Andy Shevchenko <andriy.shevche...@linux.intel.com> > Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
