On Tue, Nov 08, 2016 at 07:36:45AM +0100, Marek Szyprowski wrote: > Hi Luis, > > > On 2016-11-07 22:15, Luis R. Rodriguez wrote: > > On Wed, Nov 02, 2016 at 08:58:38AM +0100, Marek Szyprowski wrote: > > > On 2016-10-31 18:47, Greg Kroah-Hartman wrote: > > > > On Sun, Oct 30, 2016 at 05:22:13PM +0100, Rafael J. Wysocki wrote: > > > > > Let me quote from the previous intro messages for this series first: > > > > > > > > > > > > Time for another update. :-) > > > > > > > > > > > > > > Fewer changes this time, mostly to address issues found by Lukas > > > > > > > and > > > > > > > Marek. > > > > > > > > > > > > > > The most significant one is to make device_link_add() cope with > > > > > > > the case > > > > > > > when > > > > > > > the consumer device has not been registered yet when it is > > > > > > > called. The > > > > > > > supplier device still is required to be registered and the > > > > > > > function will > > > > > > > return NULL if that is not the case. > > > > > > > > > > > > > > Another significant change is in patch [4/5] that now makes the > > > > > > > core apply > > > > > > > pm_runtime_get_sync()/pm_runtime_put() to supplier devices around > > > > > > > the > > > > > > > probing of a consumer one (in analogy with the parent). > > > > > > One more update after some conversations during LinuxCon Europe. > > > > > > > > > > > > The main point was to make it possible for device_link_add() to > > > > > > figure out > > > > > > the initial state of the link instead of expecting the caller to > > > > > > provide it > > > > > > which might not be reliable enough in general. > > > > > > > > > > > > In this version device_link_add() takes three arguments, the > > > > > > supplier and > > > > > > consumer pointers and flags and it sets the correct initial state > > > > > > of the > > > > > > link automatically (unless invoked with the "stateless" flag, of > > > > > > course). > > > > > > The cost is one additional field in struct device (I moved all of > > > > > > the > > > > > > links-related fields in struct device to a separate sub-structure > > > > > > while at > > > > > > it) to track the "driver presence status" of the device (to be used > > > > > > by > > > > > > device_link_add()). > > > > > > > > > > > > In addition to that, the links list walks in the core.c and dd.c > > > > > > code are > > > > > > under the device links mutex now, so the iternal link spinlock is > > > > > > not needed > > > > > > any more and I have renamed symbols to distinguish between flags, > > > > > > link > > > > > > states and device "driver presence statuses". > > > > > The most significant change in this revision with respect to the > > > > > previous one is > > > > > related to the fact that SRCU is not available on some architectures, > > > > > so the > > > > > code falls back to using an RW semaphore for synchronization if SRCU > > > > > is not > > > > > there. Fortunately, the code changes needed for that turned out to > > > > > be quite > > > > > straightforward and confined to the second patch. > > > > > > > > > > Apart from this, the flags are defined using BIT(x) now (instead of > > > > > open coding > > > > > the latter in the flag definitions). > > > > > > > > > > Updated is mostly patch [2/5]. Patches [1,3,5/5] have not changed > > > > > (except for > > > > > trivial rebasing) and patch [4/5] needed to be refreshed on top of > > > > > the modified > > > > > [2/5]. > > > > > > > > > > FWIW, I've run the series through 0-day which has not reported any > > > > > problems > > > > > with it. > > > > Great, they are now applied to my tree, thanks again for doing this > > > > work. > > > Thanks for merging those patches! Could you provide a stable tag with > > > them, > > > so I can > > > ask Joerg to merge my Exynos IOMMU PM patches on top of it via IOMMU tree? > > You want these patches to be merged into stable?! This is a whole new set of > > functionality, the patches in no way describe any *fixes* or critical > > issues, > > why are you saying this is needed? What makes you believe this is a stable > > candidate? > > I don't want to merge those patches to stale kernel release. By 'stable tag' > I just meant something that can be pulled by Joerg to have a base for my > Exynos IOMMU patches.
Phew! Thanks for the clarification! Luis
