Am 2020-05-26 23:45, schrieb Saravana Kannan:
On Tue, May 26, 2020 at 2:13 PM Michael Walle <[email protected]> wrote:Am 2020-05-26 21:43, schrieb Saravana Kannan: > 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 <[email protected]> > Signed-off-by: Saravana Kannan <[email protected]> > --- > > v1->v2: > - Added code to "revert" the link status if consumer probe fails > > Greg, > > I think this is the issue Michael ran into. I'd like him to test the > fix > before it's pulled in. > > Michael, > > If you can test this on the branch you saw the issue in and give a > Tested-by if it works, that'd be great. with v2 I'm triggering the WARN_ON(!(link->status & DL_FLAG_SYNC_STATE_ONLY)); in __device_links_no_driver().Thanks for the logs! The WARNING is due to a dump typo in this line. I should be checking link->flags, not link->status here. I'll send out a v3, but you can test with this change too.
Ahh, right. With that fix you can add: Tested-by: Michael Walle <[email protected]> Thanks, -michael
