Re: [PATCH] irqchip/gic-v3: do not access GICR_WAKER if its secured register.

From: Srinivas Kandagatla
Date: Wed Jun 13 2018 - 06:53:44 EST




On 13/06/18 09:45, Sudeep Holla wrote:
On Wed, Jun 13, 2018 at 9:21 AM, Srinivas Kandagatla
<srinivas.kandagatla@xxxxxxxxxx> wrote:


On 12/06/18 17:34, Marc Zyngier wrote:

I suggest you find out how the GIC has been integrated on this
platform. If you take a fault on accessing this register, this very
much looks like an integration bug, and it should be quirked as such.

Thanks for the suggestion, This is a bug in the firmware which is
restricting access to this register. We have been working around this bug
for more than 2 years due to this. Now this platform support is in mainline
and We/I have no hope that this will be fixed in near future atleast for
this platform.


From what you are saying, you were aware of the firmware bug for 2 years as
you had work-around from then. I wish the firmware had come up with the fix
in those lost 2 years. I understand if it was discovered now, but that doesn't
seem to be the case here.

Firmware fixes are now becoming inevitable, so the attitude that firmware can't
be fixed has to slowing change. I am not saying I am against the quirk, but in
general I have seen the firmware support of QCOM parts are really bad. I waited
for almost 2 years for PSCI firmware on previous dragonboard where developer
are trying to upstream some feature.
I agree with you!

We did wait for more than 2 years for firmware to be fixed. But it never happened and very little hopes to get it fixed.

I did try the quirk based on GICD_IIDR and I could boot linus master on DB820c!

I will send it out as RFC soon.

thanks,
srini

--
Regards,
Sudeep