Re: [PATCH] powerpc/rtas: Introduce rtas_get_sensor_nonblocking() for pci hotplug driver.

Mahesh J Salgaonkar [off-list ref] writes:

On 2021-11-29 22:53:41 Mon, Nathan Lynch wrote:

quoted

Mahesh Salgaonkar [off-list ref] writes:

quoted

However on certain PHB failures, the rtas call get-sesnor-state() returns
extended busy error (9902) until PHB is recovered by phyp. Once PHB is
recovered, the get-sensor-state() returns success with correct presence
status. The rtas call interface rtas_get_sensor() loops over the rtas call
on extended delay return code (9902) until the return value is either
success (0) or error (-1). This causes the EEH handler to get stuck for ~6
seconds before it could notify that the pci error has been detected and
stop any active operations.

I am curious whether you see any difference with "powerpc/rtas:
rtas_busy_delay() improvements" which was recently applied. It will
cause the the calling task to sleep in response to a 990x status instead
of immediately retrying:

https://git.kernel.org/powerpc/c/38f7b7067dae0c101be573106018e8af22a90fdf

If that commit helps then maybe this change isn't needed.

I tried with above commit but it didn't help.

OK, not too surprising, but thank you for checking.