2014-02-25 10:24:03

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH 3.14 1/2] ath9k: reduce baseband hang detection false positive rate

Check if the baseband state remains stable, and add a small delay
between register reads.

Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/hw.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 11eab9f..303ce27 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1534,7 +1534,7 @@ EXPORT_SYMBOL(ath9k_hw_check_nav);
bool ath9k_hw_check_alive(struct ath_hw *ah)
{
int count = 50;
- u32 reg;
+ u32 reg, last_val;

if (AR_SREV_9300(ah))
return !ath9k_hw_detect_mac_hang(ah);
@@ -1542,9 +1542,13 @@ bool ath9k_hw_check_alive(struct ath_hw *ah)
if (AR_SREV_9285_12_OR_LATER(ah))
return true;

+ last_val = REG_READ(ah, AR_OBS_BUS_1);
do {
reg = REG_READ(ah, AR_OBS_BUS_1);
+ if (reg != last_val)
+ return true;

+ last_val = reg;
if ((reg & 0x7E7FFFEF) == 0x00702400)
continue;

@@ -1556,6 +1560,8 @@ bool ath9k_hw_check_alive(struct ath_hw *ah)
default:
return true;
}
+
+ udelay(1);
} while (count-- > 0);

return false;
--
1.8.3.4 (Apple Git-47)



2014-02-25 10:24:04

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH 3.14 2/2] ath9k: fix invalid descriptor discarding

Only set sc->rx.discard_next to rx_stats->rs_more when actually
discarding the current descriptor.

Also, fix a detection of broken descriptors:
First the code checks if the current descriptor is not done.
Then it checks if the next descriptor is done.
Add a check that afterwards checks the first descriptor again, because
it might have been completed in the mean time.

This fixes a regression introduced in
commit 723e711356b5a8a95728a890e254e8b0d47b55cf
"ath9k: fix handling of broken descriptors"

Cc: [email protected]
Reported-by: Marco AndrĂ© Dinis <[email protected]>
Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/recv.c | 70 +++++++++++++++++------------------
1 file changed, 35 insertions(+), 35 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index a0ebdd0..82e340d 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -732,11 +732,18 @@ static struct ath_rxbuf *ath_get_next_rx_buf(struct ath_softc *sc,
return NULL;

/*
- * mark descriptor as zero-length and set the 'more'
- * flag to ensure that both buffers get discarded
+ * Re-check previous descriptor, in case it has been filled
+ * in the mean time.
*/
- rs->rs_datalen = 0;
- rs->rs_more = true;
+ ret = ath9k_hw_rxprocdesc(ah, ds, rs);
+ if (ret == -EINPROGRESS) {
+ /*
+ * mark descriptor as zero-length and set the 'more'
+ * flag to ensure that both buffers get discarded
+ */
+ rs->rs_datalen = 0;
+ rs->rs_more = true;
+ }
}

list_del(&bf->list);
@@ -985,32 +992,32 @@ static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
struct ath_common *common = ath9k_hw_common(ah);
struct ieee80211_hdr *hdr;
bool discard_current = sc->rx.discard_next;
- int ret = 0;

/*
* Discard corrupt descriptors which are marked in
* ath_get_next_rx_buf().
*/
- sc->rx.discard_next = rx_stats->rs_more;
if (discard_current)
- return -EINVAL;
+ goto corrupt;
+
+ sc->rx.discard_next = false;

/*
* Discard zero-length packets.
*/
if (!rx_stats->rs_datalen) {
RX_STAT_INC(rx_len_err);
- return -EINVAL;
+ goto corrupt;
}

- /*
- * rs_status follows rs_datalen so if rs_datalen is too large
- * we can take a hint that hardware corrupted it, so ignore
- * those frames.
- */
+ /*
+ * rs_status follows rs_datalen so if rs_datalen is too large
+ * we can take a hint that hardware corrupted it, so ignore
+ * those frames.
+ */
if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) {
RX_STAT_INC(rx_len_err);
- return -EINVAL;
+ goto corrupt;
}

/* Only use status info from the last fragment */
@@ -1024,10 +1031,8 @@ static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
* This is different from the other corrupt descriptor
* condition handled above.
*/
- if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC) {
- ret = -EINVAL;
- goto exit;
- }
+ if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC)
+ goto corrupt;

hdr = (struct ieee80211_hdr *) (skb->data + ah->caps.rx_status_len);

@@ -1043,18 +1048,15 @@ static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
if (ath_process_fft(sc, hdr, rx_stats, rx_status->mactime))
RX_STAT_INC(rx_spectral);

- ret = -EINVAL;
- goto exit;
+ return -EINVAL;
}

/*
* everything but the rate is checked here, the rate check is done
* separately to avoid doing two lookups for a rate for each frame.
*/
- if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error)) {
- ret = -EINVAL;
- goto exit;
- }
+ if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
+ return -EINVAL;

if (ath_is_mybeacon(common, hdr)) {
RX_STAT_INC(rx_beacons);
@@ -1064,15 +1066,11 @@ static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
/*
* This shouldn't happen, but have a safety check anyway.
*/
- if (WARN_ON(!ah->curchan)) {
- ret = -EINVAL;
- goto exit;
- }
+ if (WARN_ON(!ah->curchan))
+ return -EINVAL;

- if (ath9k_process_rate(common, hw, rx_stats, rx_status)) {
- ret =-EINVAL;
- goto exit;
- }
+ if (ath9k_process_rate(common, hw, rx_stats, rx_status))
+ return -EINVAL;

ath9k_process_rssi(common, hw, rx_stats, rx_status);

@@ -1087,9 +1085,11 @@ static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
sc->rx.num_pkts++;
#endif

-exit:
- sc->rx.discard_next = false;
- return ret;
+ return 0;
+
+corrupt:
+ sc->rx.discard_next = rx_stats->rs_more;
+ return -EINVAL;
}

static void ath9k_rx_skb_postprocess(struct ath_common *common,
--
1.8.3.4 (Apple Git-47)