Re: [PATCH 01/16] pmac_zilog: fix unexpected irq

Finn Thain
2011-11-25T03:15:17Z

On Thu, 24 Nov 2011, Alan Cox wrote:

> Given the change should work for all hardware do we really need the
> ifdefs. Far better I would have thought to just change it so we don't
> have to maintain what is effectively two versions of the code between
> now and 2038.

I agree.

>
> So no ack from me yet - I'd like to understand the ifdef decision first.

Removing ifdefs makes the changes more invasive and the suspend/resume
code then has to be addressed, which I've avoided.

The suspend/resume code path can't be tested on m68k macs and the common
code paths I can't easily test on a powermac.

This patch should not be needed because the chip reset shouldn't leave the
tx and rx interrupts enabled. Those interrupts are explicitly enabled only
after request_irq(), so patching the master interrupt enable behaviour
should be redundant. But that's not the case in practice.

The chip reset code is already messy. I was inclined towards ifdefs and
reluctant to share more code after practical experience suggested possible
differences in the SCC/ESCC devices.

I guess I was hoping that the powermac maintainers might prefer ifdefs to
increased risk of destabilising the driver on powermacs...

But a more invasive patch would make for better code. I will see if I can
borrow a suitable PCI PowerMac.

Finn

> Otherwise it looks sensible.
>
> Alan