[PATCH 2/2] device core: Add flag to autoremove device link on supplier unbind
From: Ulf Hansson <hidden>
Date: 2018-07-04 12:55:40
Also in:
linux-arm-msm, linux-doc, linux-pm, lkml
On 27 June 2018 at 14:50, Vivek Gautam [off-list ref] wrote:
Add a flag to autoremove the device links on supplier driver unbind. This obviates the need to explicitly delete the link in the remove path. We remove these links only when the supplier's link to its consumers has gone to DL_STATE_SUPPLIER_UNBIND state. Signed-off-by: Vivek Gautam <redacted> Suggested-by: Lukas Wunner <lukas@wunner.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: linux-doc at vger.kernel.org Cc: linux-arm-kernel at lists.infradead.org Cc: linux-pm at vger.kernel.org Cc: linux-arm-msm at vger.kernel.org
Reviewed-by: Ulf Hansson <redacted> Kind regards Uffe
quoted hunk ↗ jump to hunk
--- Documentation/driver-api/device_link.rst | 4 ++++ drivers/base/core.c | 10 ++++++++++ include/linux/device.h | 2 ++ 3 files changed, 16 insertions(+)diff --git a/Documentation/driver-api/device_link.rst b/Documentation/driver-api/device_link.rst index a005b904a264..d6763272e747 100644 --- a/Documentation/driver-api/device_link.rst +++ b/Documentation/driver-api/device_link.rst@@ -86,6 +86,10 @@ automatically purged when the consumer fails to probe or later unbinds. This obviates the need to explicitly delete the link in the ``->remove`` callback or in the error path of the ``->probe`` callback. +Similarly, when the device link is added from supplier's ``->probe`` callback, +``DL_FLAG_AUTOREMOVE_SUPPLIER`` causes the device link to be automatically +purged when the supplier fails to probe or later unbinds. + Limitations ===========diff --git a/drivers/base/core.c b/drivers/base/core.c index 14c1e3151e08..e721218bf352 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c@@ -518,6 +518,16 @@ void device_links_driver_cleanup(struct device *dev) WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER); WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND); + + /* + * autoremove the links between this @dev and its consumer + * devices that are not active, i.e. where the link state + * has moved to DL_STATE_SUPPLIER_UNBIND. + */ + if (link->status == DL_STATE_SUPPLIER_UNBIND && + link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER) + kref_put(&link->kref, __device_link_del); + WRITE_ONCE(link->status, DL_STATE_DORMANT); }diff --git a/include/linux/device.h b/include/linux/device.h index 3929805cdd59..e80920452b49 100644 --- a/include/linux/device.h +++ b/include/linux/device.h@@ -787,11 +787,13 @@ enum device_link_state { * AUTOREMOVE_CONSUMER: Remove the link automatically on consumer driver unbind. * PM_RUNTIME: If set, the runtime PM framework will use this link. * RPM_ACTIVE: Run pm_runtime_get_sync() on the supplier during link creation. + * AUTOREMOVE_SUPPLIER: Remove the link automatically on supplier driver unbind. */ #define DL_FLAG_STATELESS BIT(0) #define DL_FLAG_AUTOREMOVE_CONSUMER BIT(1) #define DL_FLAG_PM_RUNTIME BIT(2) #define DL_FLAG_RPM_ACTIVE BIT(3) +#define DL_FLAG_AUTOREMOVE_SUPPLIER BIT(4) /** * struct device_link - Device link representation. --QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation