Messages in this thread | | | From | Bjorn Helgaas <> | Subject | Re: 2.6.26-rc1 regression: ISA DMA broken (bisected) | Date | Tue, 13 May 2008 17:18:39 -0600 |
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On Tuesday 13 May 2008 11:33:25 am Rene Herman wrote: > On 13-05-08 19:01, Alan Cox wrote: > > On Tue, 13 May 2008 10:59:32 -0600, Bjorn Helgaas <bjorn.helgaas@hp.com> wrote: > >> On Friday 09 May 2008 12:06:55 am Takashi Iwai wrote: > >>> Thanks for catching it. Yeah, the patch looks buggy. We had an > >>> implicit assumption that dev = NULL for ISA devices that require 24bit > >>> DMA. > >> Naive question #1: Why don't we have a struct device for these > >> ISA devices? PNP builds a struct device with DMA_24BIT_MASK > >> for ISAPNP devices. > > > > Because nobody has done the needed work to get all the old ISA drivers > > converted. I guess isa_device would actually be a platform_device > > wrapper ? > > No, isa_device is its own thing, on its own isa_bus (*). It has a struct > device * readily available though... > > (*) drivers/base/isa.c, and explanatory changelog at: > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=a5117ba7da37deb09df5eb802dace229b3fb1e9f
Thanks for the nice changelog.
isa_register_driver() currently doesn't set a DMA mask. Should it?
I only see about 35 dma_alloc_coherent() calls that pass NULL. I guess even those would be a fair amount of work to change, and I suppose there would be more that I missed.
Bjorn
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