Quoting Julian Calaby <julian.calaby@xxxxxxxxx>:
Hi Florian,
On Thu, Feb 9, 2012 at 21:54, Florian Fainelli <florian@xxxxxxxxxxx> wrote:
Hi Julian,
On 02/09/12 11:40, Julian Calaby wrote:
Hi Florian,
A couple of minor points:
On Thu, Feb 9, 2012 at 21:24, Florian Fainelli<florian@xxxxxxxxxxx>
wrote:
I am running Debian testing kernel 3.1.0-1-amd64, using a 079b:0062 Sagem
XG-76NA 802.11bg stick.
Upon zd1211rw interface
bringup (ifconfig wlan0 up) I get the following timeout:
[ 950.330573] zd1211rw 1-3:1.0: phy2
[ 955.108510] zd1211rw 1-3:1.0: firmware version 4725
[ 955.148532] zd1211rw 1-3:1.0: zd1211b chip 079b:0062 v4810 high
00-19-70
AL2230_RF pa0 g--NS
[snip]
[ 955.204072] zd1211rw 1-3:1.0: error ioread32(CR_REG1): -110
A second ifconfig wlan0 up brings the interface up without problems.
After a bit more debugging, the call trace is the following:
[10241.028130] zd1211rw 1-3:1.0: zd_chip_lock_phy_regs: error
ioread32(CR_REG1): -110
[10241.028140] zd1211rw 1-3:1.0: zd_switch_radio_on: failed to lock PHY
regs
[10241.028148] zd1211rw 1-3:1.0: zd_op_start: failed to set radio on
Adding a 10 milliseconds delay between the call to set_mc_hash() and
zd_chip_switch_radio_on() allows successful interface bringups in all
cases and matches what the vendor driver did.
Signed-off-by: Florian Fainelli<florian@xxxxxxxxxxx>
---
drivers/net/wireless/zd1211rw/zd_mac.c | 7 ++++++-
1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/drivers/net/wireless/zd1211rw/zd_mac.c
b/drivers/net/wireless/zd1211rw/zd_mac.c
index 98a574a..bed634c 100644
--- a/drivers/net/wireless/zd1211rw/zd_mac.c
+++ b/drivers/net/wireless/zd1211rw/zd_mac.c
@@ -306,9 +306,14 @@ int zd_op_start(struct ieee80211_hw *hw)
r = set_mc_hash(mac);
if (r)
goto disable_int;
+ msleep(10);
You might want to stick a comment in here to tell future developers
why we're doing this.
I was counting on the commit message to actually provide the detailed
explanation, but you are right, some comment might be appropriate here as
well.
+
r = zd_chip_switch_radio_on(chip);
- if (r< 0)
+ if (r< 0) {
+ dev_err(zd_chip_dev(chip),
+ "%s: failed to set radio on\n", __func__);
goto disable_int;
+ }
It might also be an idea to have it re-try powering on the radio
after, say 100 msecs, just in case 10 msecs isn't enough for whatever
is causing this issue.
Here I would rather let the error be printed in the kernel log for people to
report an issue if 10 msecs proves not to be enough for some systems.
When I see timing like this added to established drivers it makes me
think that maybe something has changed since the code was originally
written, maybe there was a 10msec delay somewhere deep down in the USB
code that's now been eliminated, or something else equally random, and
maybe we'll need a longer wait in the future. Writing the code to try
it, say, 5 times will probably never completely time out, but it will
probably work until the driver is removed from the kernel, rather than
having to change this to a larger value some time in the future. On
the other hand, this fixes the bug you've found and maybe something
like that can wait.
Quick search of "error ioread32(CR_REG1): -110" shows that first
reports are from 2008/2.6.24. People have found following workarounds
are "rmmod zd1211rw;modprobe zd1211rw", unplug/replug USB device, use
motherboard USB connector instead of hub, etc.
-Jussi
Thanks,
--
Julian Calaby
Email: julian.calaby@xxxxxxxxx
Profile: http://www.google.com/profiles/julian.calaby/
.Plan: http://sites.google.com/site/juliancalaby/
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