4.19-stable review patch. If anyone has any objections, please let me know.
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From: Toke Høiland-Jørgensen toke@redhat.com
[ Upstream commit f6ffe7f0184792c2f99aca6ae5b916683973d7d3 ]
We should not be checking the return values from debugfs creation at all: the debugfs functions are designed to handle errors of previously called functions and just transparently abort the creation of debugfs entries when debugfs is disabled. If we check the return value and abort driver initialisation, we break the driver if debugfs is disabled (such as when booting with debugfs=off).
Earlier versions of ath9k accidentally did the right thing by checking the return value, but only for NULL, not for IS_ERR(). This was "fixed" by the two commits referenced below, breaking ath9k with debugfs=off starting from the 6.6 kernel (as reported in the Bugzilla linked below).
Restore functionality by just getting rid of the return value check entirely.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219122 Fixes: 1e4134610d93 ("wifi: ath9k: use IS_ERR() with debugfs_create_dir()") Fixes: 6edb4ba6fb5b ("wifi: ath9k: fix parameter check in ath9k_init_debug()") Reported-by: Daniel Tobias dan.g.tob@gmail.com Tested-by: Daniel Tobias dan.g.tob@gmail.com Signed-off-by: Toke Høiland-Jørgensen toke@redhat.com Signed-off-by: Kalle Valo quic_kvalo@quicinc.com Link: https://patch.msgid.link/20240805110225.19690-1-toke@toke.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/ath/ath9k/debug.c | 2 -- drivers/net/wireless/ath/ath9k/htc_drv_debug.c | 2 -- 2 files changed, 4 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c index 1700d23f0aa9e..9440d6bfea922 100644 --- a/drivers/net/wireless/ath/ath9k/debug.c +++ b/drivers/net/wireless/ath/ath9k/debug.c @@ -1384,8 +1384,6 @@ int ath9k_init_debug(struct ath_hw *ah)
sc->debug.debugfs_phy = debugfs_create_dir("ath9k", sc->hw->wiphy->debugfsdir); - if (IS_ERR(sc->debug.debugfs_phy)) - return -ENOMEM;
#ifdef CONFIG_ATH_DEBUG debugfs_create_file("debug", 0600, sc->debug.debugfs_phy, diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c b/drivers/net/wireless/ath/ath9k/htc_drv_debug.c index e79bbcd3279af..81332086e2899 100644 --- a/drivers/net/wireless/ath/ath9k/htc_drv_debug.c +++ b/drivers/net/wireless/ath/ath9k/htc_drv_debug.c @@ -491,8 +491,6 @@ int ath9k_htc_init_debug(struct ath_hw *ah)
priv->debug.debugfs_phy = debugfs_create_dir(KBUILD_MODNAME, priv->hw->wiphy->debugfsdir); - if (IS_ERR(priv->debug.debugfs_phy)) - return -ENOMEM;
ath9k_cmn_spectral_init_debug(&priv->spec_priv, priv->debug.debugfs_phy);