This is a note to let you know that I've just added the patch titled
net: dsa: hellcreek: be compatible with masters which unregister on shutdown
to the 5.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-dsa-hellcreek-be-compatible-with-masters-which-u.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5a8fa1511bcf9d6bcf04245ccdb61b4d788c0212
Author: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Date: Fri Sep 17 16:34:34 2021 +0300
net: dsa: hellcreek: be compatible with masters which unregister on shutdown
[ Upstream commit 46baae56e1001a771a5d132aa883cb5605013ae2 ]
Since commit 2f1e8ea726e9 ("net: dsa: link interfaces with the DSA
master to get rid of lockdep warnings"), DSA gained a requirement which
it did not fulfill, which is to unlink itself from the DSA master at
shutdown time.
Since the hellcreek driver was introduced after the bad commit, it has
never worked with DSA masters which decide to unregister their
net_device on shutdown, effectively hanging the reboot process.
Hellcreek is a platform device driver, so we probably cannot have the
oddities of ->shutdown and ->remove getting both called for the exact
same struct device. But to be in line with the pattern from the other
device drivers which are on slow buses, implement the same "if this then
not that" pattern of either running the ->shutdown or the ->remove hook.
The driver's current ->remove implementation makes that very easy
because it already zeroes out its device_drvdata on ->remove.
Fixes: e4b27ebc780f ("net: dsa: Add DSA driver for Hirschmann Hellcreek switches")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@xxxxxx/
Reported-by: Lino Sanfilippo <LinoSanfilippo@xxxxxx>
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Acked-by: Kurt Kanzenbach <kurt@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/dsa/hirschmann/hellcreek.c b/drivers/net/dsa/hirschmann/hellcreek.c
index 7062db6a083c..a0f5ec4f4e58 100644
--- a/drivers/net/dsa/hirschmann/hellcreek.c
+++ b/drivers/net/dsa/hirschmann/hellcreek.c
@@ -1915,6 +1915,9 @@ static int hellcreek_remove(struct platform_device *pdev)
{
struct hellcreek *hellcreek = platform_get_drvdata(pdev);
+ if (!hellcreek)
+ return 0;
+
hellcreek_hwtstamp_free(hellcreek);
hellcreek_ptp_free(hellcreek);
dsa_unregister_switch(hellcreek->ds);
@@ -1923,6 +1926,18 @@ static int hellcreek_remove(struct platform_device *pdev)
return 0;
}
+static void hellcreek_shutdown(struct platform_device *pdev)
+{
+ struct hellcreek *hellcreek = platform_get_drvdata(pdev);
+
+ if (!hellcreek)
+ return;
+
+ dsa_switch_shutdown(hellcreek->ds);
+
+ platform_set_drvdata(pdev, NULL);
+}
+
static const struct hellcreek_platform_data de1soc_r1_pdata = {
.name = "r4c30",
.num_ports = 4,
@@ -1945,6 +1960,7 @@ MODULE_DEVICE_TABLE(of, hellcreek_of_match);
static struct platform_driver hellcreek_driver = {
.probe = hellcreek_probe,
.remove = hellcreek_remove,
+ .shutdown = hellcreek_shutdown,
.driver = {
.name = "hellcreek",
.of_match_table = hellcreek_of_match,
