You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
138 lines
4.3 KiB
138 lines
4.3 KiB
![]()
10 years ago
|
From: Sergey Ryazanov <ryazanov.s.a@gmail.com>
|
||
![]()
10 years ago
|
Date: Wed, 4 Mar 2015 05:12:10 +0300
|
||
![]()
10 years ago
|
Subject: [PATCH] ath5k: channel change fix
|
||
|
|
||
|
ath5k updates the channel pointer and after that it stops the Rx logic
|
||
|
and apply channel to HW. In case of channel switch, such sequence
|
||
|
creates a small window when a frame, which is received on the old
|
||
|
channel is considered as a frame received on the new one.
|
||
|
|
||
|
The most notable consequence of this situation occurs during the switch
|
||
|
from 2 GHz band (CCK+OFDM) to the 5GHz band (OFDM-only). Frame received
|
||
|
with CCK rate, e.g. beacon received at the 1mbps, causes the following
|
||
|
warning:
|
||
|
|
||
|
WARNING: at ath5k/base.c:589 ath5k_tasklet_rx+0x318/0x6ec [ath5k]()
|
||
|
invalid hw_rix: 1a
|
||
|
[..]
|
||
|
Call Trace:
|
||
|
[<802656a8>] show_stack+0x48/0x70
|
||
|
[<802dd92c>] warn_slowpath_common+0x88/0xbc
|
||
|
[<802dd98c>] warn_slowpath_fmt+0x2c/0x38
|
||
|
[<81b51be8>] ath5k_tasklet_rx+0x318/0x6ec [ath5k]
|
||
|
[<8028ac64>] tasklet_action+0x8c/0xf0
|
||
|
[<80075804>] __do_softirq+0x180/0x32c
|
||
|
[<80196ce8>] irq_exit+0x54/0x70
|
||
|
[<80041848>] ret_from_irq+0x0/0x4
|
||
|
[<80182fdc>] ioread32+0x4/0xc
|
||
|
[<81b4c42c>] ath5k_hw_set_sleep_clock+0x2ec/0x474 [ath5k]
|
||
|
[<81b4cf28>] ath5k_hw_reset+0x50/0xeb8 [ath5k]
|
||
|
[<81b50900>] ath5k_reset+0xd4/0x310 [ath5k]
|
||
|
[<81b557e8>] ath5k_config+0x4c/0x104 [ath5k]
|
||
|
[<80d01770>] ieee80211_hw_config+0x2f4/0x35c [mac80211]
|
||
|
[<80d09aa8>] ieee80211_scan_work+0x2e4/0x414 [mac80211]
|
||
|
[<8022c3f4>] process_one_work+0x28c/0x400
|
||
|
[<802df8f8>] worker_thread+0x258/0x3c0
|
||
|
[<801b5710>] kthread+0xe0/0xec
|
||
|
[<800418a8>] ret_from_kernel_thread+0x14/0x1c
|
||
|
|
||
|
The easiest way to reproduce this warning is to run scan with dualband
|
||
|
NIC in noisy environments, when the channel 11 runs multiple APs. In my
|
||
|
tests if the APs num >= 12, the warning appears in the first few
|
||
|
seconds of scanning.
|
||
|
|
||
|
In order to fix this, the Rx disable code moved to a higher level and
|
||
|
placed before the channel pointer update. This is also makes the code a
|
||
|
bit more symmetrical, since we disable and enable the Rx in the same
|
||
|
function.
|
||
|
|
||
|
In fact, at the pointer update time new frames should not appear,
|
||
|
because interrupt generation at this point should already be disabled.
|
||
|
The next patch should address this issue.
|
||
|
|
||
|
CC: Jiri Slaby <jirislaby@gmail.com>
|
||
|
CC: Nick Kossifidis <mickflemm@gmail.com>
|
||
|
CC: Luis R. Rodriguez <mcgrof@do-not-panic.com>
|
||
|
Reported-by: Christophe Prevotaux <cprevotaux@nltinc.com>
|
||
|
Tested-by: Christophe Prevotaux <cprevotaux@nltinc.com>
|
||
|
Tested-by: Eric Bree <ebree@nltinc.com>
|
||
|
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
|
||
|
---
|
||
|
|
||
|
--- a/drivers/net/wireless/ath/ath5k/base.c
|
||
|
+++ b/drivers/net/wireless/ath/ath5k/base.c
|
||
![]()
10 years ago
|
@@ -2858,7 +2858,7 @@ ath5k_reset(struct ath5k_hw *ah, struct
|
||
![]()
10 years ago
|
{
|
||
|
struct ath_common *common = ath5k_hw_common(ah);
|
||
|
int ret, ani_mode;
|
||
|
- bool fast;
|
||
|
+ bool fast = chan && modparam_fastchanswitch ? 1 : 0;
|
||
|
|
||
|
ATH5K_DBG(ah, ATH5K_DEBUG_RESET, "resetting\n");
|
||
|
|
||
![]()
10 years ago
|
@@ -2876,11 +2876,29 @@ ath5k_reset(struct ath5k_hw *ah, struct
|
||
![]()
10 years ago
|
* so we should also free any remaining
|
||
|
* tx buffers */
|
||
|
ath5k_drain_tx_buffs(ah);
|
||
|
+
|
||
|
+ /* Stop PCU */
|
||
|
+ ath5k_hw_stop_rx_pcu(ah);
|
||
|
+
|
||
|
+ /* Stop DMA
|
||
|
+ *
|
||
|
+ * Note: If DMA didn't stop continue
|
||
|
+ * since only a reset will fix it.
|
||
|
+ */
|
||
|
+ ret = ath5k_hw_dma_stop(ah);
|
||
|
+
|
||
|
+ /* RF Bus grant won't work if we have pending
|
||
|
+ * frames
|
||
|
+ */
|
||
|
+ if (ret && fast) {
|
||
|
+ ATH5K_DBG(ah, ATH5K_DEBUG_RESET,
|
||
|
+ "DMA didn't stop, falling back to normal reset\n");
|
||
|
+ fast = false;
|
||
|
+ }
|
||
|
+
|
||
|
if (chan)
|
||
|
ah->curchan = chan;
|
||
|
|
||
|
- fast = ((chan != NULL) && modparam_fastchanswitch) ? 1 : 0;
|
||
|
-
|
||
|
ret = ath5k_hw_reset(ah, ah->opmode, ah->curchan, fast, skip_pcu);
|
||
|
if (ret) {
|
||
|
ATH5K_ERR(ah, "can't reset hardware (%d)\n", ret);
|
||
|
--- a/drivers/net/wireless/ath/ath5k/reset.c
|
||
|
+++ b/drivers/net/wireless/ath/ath5k/reset.c
|
||
![]()
10 years ago
|
@@ -1169,30 +1169,6 @@ ath5k_hw_reset(struct ath5k_hw *ah, enum
|
||
![]()
10 years ago
|
if (ah->ah_version == AR5K_AR5212)
|
||
|
ath5k_hw_set_sleep_clock(ah, false);
|
||
|
|
||
|
- /*
|
||
|
- * Stop PCU
|
||
|
- */
|
||
|
- ath5k_hw_stop_rx_pcu(ah);
|
||
|
-
|
||
|
- /*
|
||
|
- * Stop DMA
|
||
|
- *
|
||
|
- * Note: If DMA didn't stop continue
|
||
|
- * since only a reset will fix it.
|
||
|
- */
|
||
|
- ret = ath5k_hw_dma_stop(ah);
|
||
|
-
|
||
|
- /* RF Bus grant won't work if we have pending
|
||
|
- * frames */
|
||
|
- if (ret && fast) {
|
||
|
- ATH5K_DBG(ah, ATH5K_DEBUG_RESET,
|
||
|
- "DMA didn't stop, falling back to normal reset\n");
|
||
|
- fast = false;
|
||
|
- /* Non fatal, just continue with
|
||
|
- * normal reset */
|
||
|
- ret = 0;
|
||
|
- }
|
||
|
-
|
||
|
mode = channel->hw_value;
|
||
|
switch (mode) {
|
||
|
case AR5K_MODE_11A:
|