diff options
| author |   Saravana Kannan <saravanak@google.com> | 2021-03-02 13:11:30 -0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-23 14:58:10 +0100 |
| commit | f2db85b64f0af1410ccb8ebcc9d7fa38e99feee9 (patch) | |
| tree | 113e0dc325b8c52029fcc9c8e043f35c3cd841c4 | |
| parent | devtmpfs: actually reclaim some init memory (diff) | |
| download | linux-rng-f2db85b64f0af1410ccb8ebcc9d7fa38e99feee9.tar.xz linux-rng-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>
| -rw-r--r-- | drivers/base/dd.c | 6 | ||||
| -rw-r--r-- | include/linux/device.h | 4 |
2 files changed, 10 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); diff --git a/include/linux/device.h b/include/linux/device.h index a8ce0dc3b758..38a2071cf776 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -439,6 +439,9 @@ struct dev_links_info { * @state_synced: The hardware state of this device has been synced to match * the software state of this device by calling the driver/bus * sync_state() callback. + * @can_match: The device has matched with a driver at least once or it is in + * a bus (like AMBA) which can't check for matching drivers until + * other devices probe successfully. * @dma_coherent: this particular device is dma coherent, even if the * architecture supports non-coherent devices. * @dma_ops_bypass: If set to %true then the dma_ops are bypassed for the @@ -545,6 +548,7 @@ struct device { bool offline:1; bool of_node_reused:1; bool state_synced:1; + bool can_match:1; #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) |