safe0 and kernel panic

[Sam Leffler]

Rajkumar S wrote:
> On 3/22/07, Sam Leffler <sam at errno.com> wrote:
>> I have no context.  I see a device not attaching for some reason.  Then
>> /dev/crypto not being present (is cryptodev loaded in the kernel?).  But
>> a subject line about a panic.
> 
> The device is not attaching because bus_dma_tag_create function fails
> with the error ENOMEM. (in line 300, safe.c). I have changed
> BUS_DMA_ALLOCNOW flag in bus_dma_tag_create to BUS_DMA_COHERENT and
> the panic disappears. BUS_DMA_COHERENT was just taken randomly (as in
> some other flag) with no idea about it's use or purpose.

Removing BUS_DMA_ALLOCNOW appears to just just hide the problem by
deferring the allocation.  Since other drivers are getting similar
failures it's unlikely this is a safe bug.

> 
>> If you've submitted a PR please send me a pointer.  Otherwise you might
>> consider submitting one w/ details like what version of freebsd you're
>> running.
> 
> The PR Number is 110662. I have tried to put as much information as
> possible, I am always ready to provide additional details or do some
> testing/debugging.

Thank you.  I'll have to dig out one of my cards to test.

	Sam