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authorSergey Ryazanov <ryazanov.s.a@gmail.com>2015-02-04 00:21:13 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-18 13:22:35 +0100
commit868fd3d3e338c81232050a0519b86e7d6b6462be (patch)
parent8686fc3d2fb81fbcc91f873d7227069d21fc2fcf (diff)
ath5k: fix spontaneus AR5312 freezes
commit 8bfae4f9938b6c1f033a5159febe97e441d6d526 upstream. Sometimes while CPU have some load and ath5k doing the wireless interface reset the whole WiSoC completely freezes. Set of tests shows that using atomic delay function while we wait interface reset helps to avoid such freezes. The easiest way to reproduce this issue: create a station interface, start continous scan with wpa_supplicant and load CPU by something. Or just create multiple station interfaces and put them all in continous scan. This patch partially reverts the commit 1846ac3dbec0 ("ath5k: Use usleep_range where possible"), which replaces initial udelay() by usleep_range(). I do not know actual source of this issue, but all looks like that HW freeze is caused by transaction on internal SoC bus, while wireless block is in reset state. Also I should note that I do not know how many chips are affected, but I did not see this issue with chips, other than AR5312. CC: Jiri Slaby <jirislaby@gmail.com> CC: Nick Kossifidis <mickflemm@gmail.com> CC: Luis R. Rodriguez <mcgrof@do-not-panic.com> Fixes: 1846ac3dbec0 ("ath5k: Use usleep_range where possible") Reported-by: Christophe Prevotaux <c.prevotaux@rural-networks.com> Tested-by: Christophe Prevotaux <c.prevotaux@rural-networks.com> Tested-by: Eric Bree <ebree@nltinc.com> Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/wireless/ath/ath5k/reset.c b/drivers/net/wireless/ath/ath5k/reset.c
index a3399c4f13a9..b9b651ea9851 100644
--- a/drivers/net/wireless/ath/ath5k/reset.c
+++ b/drivers/net/wireless/ath/ath5k/reset.c
@@ -478,7 +478,7 @@ ath5k_hw_wisoc_reset(struct ath5k_hw *ah, u32 flags)
regval = ioread32(reg);
iowrite32(regval | val, reg);
regval = ioread32(reg);
- usleep_range(100, 150);
+ udelay(100); /* NB: should be atomic */
/* Bring BB/MAC out of reset */
iowrite32(regval & ~val, reg);