[PATCH RFC] device reset in islpci_mgt_transaction()

Denis Vlasenko vda
Mon Jul 26 12:52:16 PDT 2004


Hi Jouni, Luis, Margit, Andreas,

prism54 was reported to sometimes die with iwconfig
no longer reporting any Wireless Extensions and
nothing working anymore. This can be fixed by fulfilling
TODO in islpci_mgt_transaction().

I did a patch (attached below) which does a reset
if hw times out.

Patch is not good enough for inclusion because:

1. Hang is detected and reset is triggered
only if islpci_mgt_transaction() is called from
somewhere (iwconfig <iface> will do). In 
pure acx100->prism54 flood test (no prism->acx
traffic at all), islpci_mgt_transaction() is never called
(or at least never times out).
Do we need a watchdog to periodically poll prism54 hw?

2. Busy-waiting is dirty.

Patch in action:

Jul 26 21:36:06 shadow kernel: Tx error occurred (error 0x20)!! (excessive Tx retries due to either distance too high or unable to Tx or Tx fr
Jul 26 21:36:18 shadow last message repeated 131 times
Jul 26 21:36:22 shadow kernel: ifp: timeout waiting for mgmt response 1000, triggering device
Jul 26 21:36:23 shadow default.hotplug[4078]: invoke /usr/app/hotplug-2004_01_05/script/firmware.agent ()
Jul 26 21:36:23 shadow kernel: ifp: timeout waiting for mgmt response
Jul 26 21:36:23 shadow kernel: ifp: scheduling a reset
Jul 26 21:36:23 shadow kernel: ifp: waiting for a reset to happen
Jul 26 21:36:23 shadow kernel: ifp: resetting device...
Jul 26 21:36:23 shadow kernel: ifp: uploading firmware...
Jul 26 21:36:23 shadow firmware.agent[4078]: /usr/app/hotplug-2004_01_05/firmware/isl3890 found, loading it into /sys//class/firmware/0000:00:
Jul 26 21:36:23 shadow kernel: ifp: firmware uploaded done, now triggering reset...
Jul 26 21:36:23 shadow default.hotplug[4093]: invoke /usr/app/hotplug-2004_01_05/script/firmware.agent ()
Jul 26 21:36:23 shadow kernel: ifp: reset done. Waited: 374 jiffies, 1721392 yields

Good news is that after reset card is happily doing its AP work.
Frankly, I didn't expect it to.
--
vda
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