[PATCH v3 1/2] wifi: ath9k: stop a failed register read from opening the RX filter
From: Nerijus Bendžiūnas <hidden>
Date: 2026-09-11 01:48:40
Also in:
lkml, stable
Subsystem:
atheros ath generic utilities, qualcomm atheros ath9k wireless driver, the rest · Maintainers:
Jeff Johnson, Toke Høiland-Jørgensen, Linus Torvalds
On USB a register read is a WMI round trip and a timeout returns -1.
The spectral trigger reads AR_RX_FILTER back, ORs in the PHY error
bits and writes it, so a timed-out read stores 0xffffffff and the
device forwards every frame and PHY error to the host.
Add ath9k_hw_enable_rxfilter(), which sets the requested bits with
REG_SET_BIT() and reads nothing back, and use it in the trigger. With
firmware 1.4 and later the read-modify-write is done by the firmware;
older firmware still reads from the host.
Fixes: e93d083f42a1 ("ath9k: add spectral scan feature")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Nerijus Bendžiūnas <redacted>
---
.../net/wireless/ath/ath9k/common-spectral.c | 7 ++----
drivers/net/wireless/ath/ath9k/hw.c | 23 +++++++++++++++++++
drivers/net/wireless/ath/ath9k/hw.h | 1 +
3 files changed, 26 insertions(+), 5 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/common-spectral.c b/drivers/net/wireless/ath/ath9k/common-spectral.c
index ca01a07f6630..73c1eb4ebe0e 100644
--- a/drivers/net/wireless/ath/ath9k/common-spectral.c
+++ b/drivers/net/wireless/ath/ath9k/common-spectral.c@@ -716,7 +716,6 @@ void ath9k_cmn_spectral_scan_trigger(struct ath_common *common, struct ath_spec_scan_priv *spec_priv) { struct ath_hw *ah = spec_priv->ah; - u32 rxfilter; if (IS_ENABLED(CONFIG_ATH9K_TX99)) return;
@@ -730,10 +729,8 @@ void ath9k_cmn_spectral_scan_trigger(struct ath_common *common, return; ath_ps_ops(common)->wakeup(common); - rxfilter = ath9k_hw_getrxfilter(ah); - ath9k_hw_setrxfilter(ah, rxfilter | - ATH9K_RX_FILTER_PHYRADAR | - ATH9K_RX_FILTER_PHYERR); + ath9k_hw_enable_rxfilter(ah, ATH9K_RX_FILTER_PHYRADAR | + ATH9K_RX_FILTER_PHYERR); /* TODO: usually this should not be necessary, but for some reason * (or in some mode?) the trigger must be called after the
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index e08ab73fcacb..d62b6ff00d41 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c@@ -2905,6 +2905,29 @@ void ath9k_hw_setrxfilter(struct ath_hw *ah, u32 bits) } EXPORT_SYMBOL(ath9k_hw_setrxfilter); +/* + * Set bits in the RX filter without reading it back: on USB a failed read + * returns all ones, and writing that back would open every filter bit. + */ +void ath9k_hw_enable_rxfilter(struct ath_hw *ah, u32 bits) +{ + u32 phybits = 0; + + if (bits & ATH9K_RX_FILTER_PHYRADAR) + phybits |= AR_PHY_ERR_RADAR; + if (bits & ATH9K_RX_FILTER_PHYERR) + phybits |= AR_PHY_ERR_OFDM_TIMING | AR_PHY_ERR_CCK_TIMING; + + REG_SET_BIT(ah, AR_RX_FILTER, bits); + + if (phybits) { + REG_SET_BIT(ah, AR_PHY_ERR, phybits); + /* PHY errors are reported in zero length frames. */ + REG_SET_BIT(ah, AR_RXCFG, AR_RXCFG_ZLFDMA); + } +} +EXPORT_SYMBOL(ath9k_hw_enable_rxfilter); + bool ath9k_hw_phy_disable(struct ath_hw *ah) { if (ath9k_hw_mci_is_enabled(ah))
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index b942b8303d8f..f102f73a0114 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h@@ -1055,6 +1055,7 @@ void ath9k_hw_get_channel_centers(struct ath_hw *ah, struct chan_centers *centers); u32 ath9k_hw_getrxfilter(struct ath_hw *ah); void ath9k_hw_setrxfilter(struct ath_hw *ah, u32 bits); +void ath9k_hw_enable_rxfilter(struct ath_hw *ah, u32 bits); bool ath9k_hw_phy_disable(struct ath_hw *ah); bool ath9k_hw_disable(struct ath_hw *ah); void ath9k_hw_set_txpowerlimit(struct ath_hw *ah, u32 limit, bool test);
--
2.55.0