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authorSaravana Kannan <saravanak@google.com>2021-03-02 22:11:30 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-03-23 14:58:10 +0100
commitf2db85b64f0af1410ccb8ebcc9d7fa38e99feee9 (patch)
tree113e0dc325b8c52029fcc9c8e043f35c3cd841c4 /drivers/base/dd.c
parentdevtmpfs: actually reclaim some init memory (diff)
downloadlinux-f2db85b64f0af1410ccb8ebcc9d7fa38e99feee9.tar.xz
linux-f2db85b64f0af1410ccb8ebcc9d7fa38e99feee9.zip
driver core: Avoid pointless deferred probe attempts
There's no point in adding a device to the deferred probe list if we know for sure that it doesn't have a matching driver. So, check if a device can match with a driver before adding it to the deferred probe list. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210302211133.2244281-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/dd.c')
-rw-r--r--drivers/base/dd.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 66c31cda5462..83a68e980d04 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -122,6 +122,9 @@ static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
void driver_deferred_probe_add(struct device *dev)
{
+ if (!dev->can_match)
+ return;
+
mutex_lock(&deferred_probe_mutex);
if (list_empty(&dev->p->deferred_probe)) {
dev_dbg(dev, "Added to deferred list\n");
@@ -725,6 +728,7 @@ static int driver_probe_device(struct device_driver *drv, struct device *dev)
if (!device_is_registered(dev))
return -ENODEV;
+ dev->can_match = true;
pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
drv->bus->name, __func__, dev_name(dev), drv->name);
@@ -828,6 +832,7 @@ static int __device_attach_driver(struct device_driver *drv, void *_data)
return 0;
} else if (ret == -EPROBE_DEFER) {
dev_dbg(dev, "Device match requests probe deferral\n");
+ dev->can_match = true;
driver_deferred_probe_add(dev);
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);
@@ -1063,6 +1068,7 @@ static int __driver_attach(struct device *dev, void *data)
return 0;
} else if (ret == -EPROBE_DEFER) {
dev_dbg(dev, "Device match requests probe deferral\n");
+ dev->can_match = true;
driver_deferred_probe_add(dev);
} else if (ret < 0) {
dev_dbg(dev, "Bus failed to match device: %d\n", ret);