Messages in this thread | | | From | Saravana Kannan <> | Date | Thu, 28 May 2020 09:09:21 -0700 | Subject | Re: [PATCH v3] driver core: Update device link status correctly for SYNC_STATE_ONLY links |
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On Wed, May 27, 2020 at 1:26 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > On Wed, May 27, 2020 at 12:09 AM Saravana Kannan <saravanak@google.com> wrote: > > > > When SYNC_STATE_ONLY support was added in commit 05ef983e0d65 ("driver > > core: Add device link support for SYNC_STATE_ONLY flag"), > > SYNC_STATE_ONLY links were treated similar to STATELESS links in terms > > of not blocking consumer probe if the supplier hasn't probed yet. > > > > That caused a SYNC_STATE_ONLY device link's status to not get updated. > > Since SYNC_STATE_ONLY device link is no longer useful once the > > consumer probes, commit 21c27f06587d ("driver core: Fix > > SYNC_STATE_ONLY device link implementation") addresses the status > > update issue by deleting the SYNC_STATE_ONLY device link instead of > > complicating the status update code. > > > > However, there are still some cases where we need to update the status > > of a SYNC_STATE_ONLY device link. This is because a SYNC_STATE_ONLY > > device link can later get converted into a normal MANAGED device link > > when a normal MANAGED device link is created between a supplier and > > consumer that already have a SYNC_STATE_ONLY device link between them. > > > > If a SYNC_STATE_ONLY device link's status isn't maintained correctly > > till it's converted to a normal MANAGED device link, then the normal > > MANAGED device link will end up with a wrong link status. This can cause > > a warning stack trace[1] when the consumer device probes successfully. > > > > This commit fixes the SYNC_STATE_ONLY device link status update issue > > where it wouldn't transition correctly from DL_STATE_DORMANT or > > DL_STATE_AVAILABLE to DL_STATE_CONSUMER_PROBE. It also resets the status > > back to DL_STATE_DORMANT or DL_STATE_AVAILABLE if the consumer probe > > fails. > > > > [1] - https://lore.kernel.org/lkml/20200522204120.3b3c9ed6@apollo/ > > Fixes: 05ef983e0d65 ("driver core: Add device link support for SYNC_STATE_ONLY flag") > > Fixes: 21c27f06587d ("driver core: Fix SYNC_STATE_ONLY device link implementation") > > Reported-by: Michael Walle <michael@walle.cc> > > Tested-by: Michael Walle <michael@walle.cc> > > Signed-off-by: Saravana Kannan <saravanak@google.com> > > Reviewed-by: Rafael J. Wysocki <rrafael.j.wysocki@intel.com> >
Thanks Rafael for the review.
And thanks again Michael for all the logs!
-Saravana
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