From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@kernel.org (Kevin Hilman) Date: Tue, 08 Dec 2015 10:59:00 -0800 Subject: [PATCH v2 1/5] power: domain: add pm_genpd_exit In-Reply-To: <5665599A.4060509@nvidia.com> (Jon Hunter's message of "Mon, 7 Dec 2015 10:04:10 +0000") References: <1449251148-19344-1-git-send-email-eric@anholt.net> <1449251148-19344-2-git-send-email-eric@anholt.net> <5665599A.4060509@nvidia.com> Message-ID: <7h8u54lqbv.fsf@deeprootsystems.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Jon Hunter writes: > On 04/12/15 17:45, Eric Anholt wrote: >> From: Alexander Aring >> >> This patch adds function pm_genpd_exit for undo a pm_genpd_init. This >> is useful for multiple power domains while probing. If the probing fails >> after one pm_genpd_init was called we need to undo all previous >> registrations of generic pm domains inside the gpd_list list. >> >> There is a check on IS_ERR_OR_NULL(genpd) which is useful to check again >> registered power domains and not registered domains, the driver can use >> this mechanism to have an array with registered and non-registered power >> domains, where non-registered power domains are NULL. >> >> Cc: Rafael J. Wysocki >> Cc: Kevin Hilman >> Cc: Ulf Hansson >> Cc: Pavel Machek >> Cc: Len Brown >> Cc: Greg Kroah-Hartman >> Signed-off-by: Alexander Aring >> Signed-off-by: Eric Anholt >> Acked-by: Ulf Hansson >> --- >> drivers/base/power/domain.c | 22 ++++++++++++++++++++++ >> include/linux/pm_domain.h | 4 ++++ >> 2 files changed, 26 insertions(+) >> >> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c >> index 167418e..e7aca27 100644 >> --- a/drivers/base/power/domain.c >> +++ b/drivers/base/power/domain.c >> @@ -1509,6 +1509,28 @@ void pm_genpd_init(struct generic_pm_domain *genpd, >> } >> EXPORT_SYMBOL_GPL(pm_genpd_init); >> >> +/** >> + * pm_genpd_exit - Uninitialize a generic I/O PM domain object. >> + * @genpd: PM domain object to uninitialize. >> + */ >> +void pm_genpd_exit(struct generic_pm_domain *genpd) >> +{ >> + if (IS_ERR_OR_NULL(genpd)) >> + return; >> + >> + /* check if domain is still in registered inside the pm subsystem */ >> + WARN_ON_ONCE(!list_empty(&genpd->master_links) || >> + !list_empty(&genpd->slave_links) || >> + !list_empty(&genpd->dev_list)); >> + > > Why not return an error here? Seems bad to remove it, if it could still > be referenced by other domains. I had pointed this out as well in an earlier review. > Also not sure if you need to lock around the above test and removing the > domain. > >> + mutex_lock(&gpd_list_lock); >> + list_del(&genpd->gpd_list_node); >> + mutex_unlock(&gpd_list_lock); >> + >> + mutex_destroy(&genpd->lock); >> +} >> +EXPORT_SYMBOL_GPL(pm_genpd_exit); >> + > > BTW, I had just submitted a similar patch here [0]. So I would also like > to see such an API added. Between the two of you, maybe come up with an agreed upon patch and re-submit. Kevin > Cheers > Jon > > [0] http://marc.info/?l=devicetree&m=144924138932726&w=2