diff mbox series

[net-next,6/6] net: ipa: add driver shutdown callback

Message ID 20201119224929.23819-7-elder@linaro.org (mailing list archive)
State Accepted
Commit ae1d72f9779fbd05808517c030a2dae327cb038d
Delegated to: Netdev Maintainers
Headers show
Series net: ipa: add a driver shutdown callback | expand

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netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 26 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
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netdev/stable success Stable not CCed

Commit Message

Alex Elder Nov. 19, 2020, 10:49 p.m. UTC
A system shutdown can happen at essentially any time, and it's
possible that the IPA driver is busy when a shutdown is underway.
IPA hardware accesses IMEM and SMEM memory regions using an IOMMU,
and at some point during shutdown, needed I/O mappings could become
invalid.  This could be disastrous for any "in flight" IPA activity.

Avoid this by defining a new driver shutdown callback that stops all
IPA activity and cleanly shuts down the driver.  It merely calls the
driver's existing remove callback, reporting the error if it returns
one.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_main.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index 9f4bd822ac625..bbfc071fa2a60 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -889,6 +889,15 @@  static int ipa_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static void ipa_shutdown(struct platform_device *pdev)
+{
+	int ret;
+
+	ret = ipa_remove(pdev);
+	if (ret)
+		dev_err(&pdev->dev, "shutdown: remove returned %d\n", ret);
+}
+
 /**
  * ipa_suspend() - Power management system suspend callback
  * @dev:	IPA device structure
@@ -946,8 +955,9 @@  static const struct dev_pm_ops ipa_pm_ops = {
 };
 
 static struct platform_driver ipa_driver = {
-	.probe	= ipa_probe,
-	.remove	= ipa_remove,
+	.probe		= ipa_probe,
+	.remove		= ipa_remove,
+	.shutdown	= ipa_shutdown,
 	.driver	= {
 		.name		= "ipa",
 		.pm		= &ipa_pm_ops,