Re: Parallel ATA with libata status with the patches I'm working on

From: Russell King
Date: Fri Nov 04 2005 - 18:10:51 EST


On Fri, Nov 04, 2005 at 01:41:06PM +0000, Alan Cox wrote:
> While writing the new sl82c05 driver I noticed a real nasty lurking in
> the old code. According to the errata docs you have to reset the DMA
> engine every transfer to work around chip errata. It also says that this
> resets any other ATA transfer in progress.
>
> If both channels are in use there is no locking between the channels to
> stop a reset on one channel as DMA begins making a mess of the other
> channel. Looks like serialize should be set on the driver ?

Possibly, though benh needs to comment. (I think benh has the only
hardware which has the possibility of both channels - the NetWinder
only has one channel with one disk.)

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
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