Re: [PATCH] thunderbolt: Reduce retry timeout to speed up boot for some devices

From: Werner Sembach
Date: Wed Dec 20 2023 - 11:41:54 EST



Am 20.12.23 um 17:04 schrieb Greg KH:
On Wed, Dec 20, 2023 at 04:23:15PM +0100, Werner Sembach wrote:
Am 20.12.23 um 16:09 schrieb Werner Sembach:
This is a followup to "thunderbolt: Workaround an IOMMU fault on certain
systems with Intel Maple Ridge".

It seems like the timeout can be reduced to 250ms. This reduces the overall
delay caused by the retires to ~1s. This is about the time other things
being initialized in parallel need anyway*, so like this the effective boot
time is no longer compromised.

*I only had a single device available for my measurements: A Clevo X170KM-G
desktop replacement notebook.

Signed-off-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
I wonder if this could also land in stable? Or would it be to risky?
If it's really a bugfix now, why would it _not_ be relevant for stable?

Because it changes a timeout that could cause issues if set to low: This Patch sets to to 250ms. Set to 50ms it causes issues, currently it's 2000ms, 2 people tested that 250ms is enough, but i don't know if this is a big enough sample size for stable.

The advantage is significantly faster boot time on affected devices (~12s down to ~3s), however they do already work fine without it.

Kind regards,

Werner


thanks,

greg k-h