Merge tag 'scmi-fixes-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/fixes

Arm SCMI fixes for v6.1

A bunch of fixes to handle:
1. A possible resource leak in scmi_remove(). The returned error
   value gets ignored by the driver core and can remove the device and
   free the devm-allocated resources. As a simple solution to be able to
   easily backport, the bind attributes in the driver is suppressed as
   there is no need to support it. Additionally the remove path is cleaned
   up by adding device links between the core and the protocol devices
   so that a proper and complete unbinding happens.
2. A possible spin-loop in the SCMI transmit path in case of misbehaving
   platform firmware. A timeout is added to the existing loop so that
   the SCMI stack can bailout aborting the transmission with warnings.
3. Optional Rx channel correctly by reporting any memory errors instead
   of ignoring the same with other allowed errors.
4. The use of proper device for all the device managed allocations in the
   virtio transport.
5. Incorrect deferred_tx_wq release on the error paths by using devres
   API(devm_add_action_or_reset) to manage the release in the error path.

* tag 'scmi-fixes-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  firmware: arm_scmi: Fix deferred_tx_wq release on error paths
  firmware: arm_scmi: Fix devres allocation device in virtio transport
  firmware: arm_scmi: Make Rx chan_setup fail on memory errors
  firmware: arm_scmi: Make tx_prepare time out eventually
  firmware: arm_scmi: Suppress the driver's bind attributes
  firmware: arm_scmi: Cleanup the core driver removal callback

Link: https://lore.kernel.org/r/20221102140142.2758107-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 27 insertions, 14 deletions

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 609ebedee9cb..f818d00bb2c6 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2013,6 +2013,7 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
 		return -ENOMEM;
 
 	cinfo->dev = dev;
+	cinfo->rx_timeout_ms = info->desc->max_rx_timeout_ms;
 
 	ret = info->desc->ops->chan_setup(cinfo, info->dev, tx);
 	if (ret)
@@ -2044,8 +2045,12 @@ scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
 {
 	int ret = scmi_chan_setup(info, dev, prot_id, true);
 
-	if (!ret) /* Rx is optional, hence no error check */
-		scmi_chan_setup(info, dev, prot_id, false);
+	if (!ret) {
+		/* Rx is optional, report only memory errors */
+		ret = scmi_chan_setup(info, dev, prot_id, false);
+		if (ret && ret != -ENOMEM)
+			ret = 0;
+	}
 
 	return ret;
 }
@@ -2273,10 +2278,16 @@ int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 			sdev = scmi_get_protocol_device(child, info,
 							id_table->protocol_id,
 							id_table->name);
-			/* Set handle if not already set: device existed */
-			if (sdev && !sdev->handle)
-				sdev->handle =
-					scmi_handle_get_from_info_unlocked(info);
+			if (sdev) {
+				/* Set handle if not already set: device existed */
+				if (!sdev->handle)
+					sdev->handle =
+						scmi_handle_get_from_info_unlocked(info);
+				/* Relink consumer and suppliers */
+				if (sdev->handle)
+					scmi_device_link_add(&sdev->dev,
+							     sdev->handle->dev);
+			}
 		} else {
 			dev_err(info->dev,
 				"Failed. SCMI protocol %d not active.\n",
@@ -2475,20 +2486,17 @@ void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id)
 
 static int scmi_remove(struct platform_device *pdev)
 {
-	int ret = 0, id;
+	int ret, id;
 	struct scmi_info *info = platform_get_drvdata(pdev);
 	struct device_node *child;
 
 	mutex_lock(&scmi_list_mutex);
 	if (info->users)
-		ret = -EBUSY;
-	else
-		list_del(&info->node);
+		dev_warn(&pdev->dev,
+			 "Still active SCMI users will be forcibly unbound.\n");
+	list_del(&info->node);
 	mutex_unlock(&scmi_list_mutex);
 
-	if (ret)
-		return ret;
-
 	scmi_notification_exit(&info->handle);
 
 	mutex_lock(&info->protocols_mtx);
@@ -2500,7 +2508,11 @@ static int scmi_remove(struct platform_device *pdev)
 	idr_destroy(&info->active_protocols);
 
 	/* Safe to free channels since no more users */
-	return scmi_cleanup_txrx_channels(info);
+	ret = scmi_cleanup_txrx_channels(info);
+	if (ret)
+		dev_warn(&pdev->dev, "Failed to cleanup SCMI channels.\n");
+
+	return 0;
 }
 
 static ssize_t protocol_version_show(struct device *dev,
@@ -2571,6 +2583,7 @@ MODULE_DEVICE_TABLE(of, scmi_of_match);
 static struct platform_driver scmi_driver = {
 	.driver = {
 		   .name = "arm-scmi",
+		   .suppress_bind_attrs = true,
 		   .of_match_table = scmi_of_match,
 		   .dev_groups = versions_groups,
 		   },