| Message ID | 20210912120932.993440-4-vladimir.oltean@nxp.com |
|---|---|
| State | New |
| Headers | show |
| Series | Make DSA switch drivers compatible with masters which unregister on shutdown | expand |
On Sun Sep 12 2021, Vladimir Oltean wrote: > 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@gmx.de/ > Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Kurt Kanzenbach <kurt@linutronix.de>
diff --git a/drivers/net/dsa/hirschmann/hellcreek.c b/drivers/net/dsa/hirschmann/hellcreek.c index 542cfc4ccb08..354655f9ed00 100644 --- a/drivers/net/dsa/hirschmann/hellcreek.c +++ b/drivers/net/dsa/hirschmann/hellcreek.c @@ -1916,6 +1916,9 @@ 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); @@ -1924,6 +1927,18 @@ 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, @@ -1946,6 +1961,7 @@ 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,
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@gmx.de/ Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- drivers/net/dsa/hirschmann/hellcreek.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)