commit "iwlwifi: uCode Alive notification with timeout" introduced a more
reliable mechanism for ucode loading. Unfortunately we hit a problem with
it frequently enough to make a 4965 unusable. The problem can be seen in
debug log below. What this code attempts is to set runtime ucode up to
load, start a timer to wait for the alive response from runtime ucode, and
if it times out it tries again. As can be seen below we receive the alive
response and wake the waiting task _before_ the tasks starts waiting. The
task thus times out as the alive response is not received while it is
waiting for it and it restarts the device. This starts the cycle all over
again.

[29739.000819] ieee80211 phy0: U iwl_mac_start enter
[29739.005751] ieee80211 phy0: U iwl_prepare_card_hw iwl_prepare_card_hw enter
[29739.012798] ieee80211 phy0: U iwl_set_hw_ready hardware ready
[29739.057200] ieee80211 phy0: U iwl4965_load_bsm Begin load bsm
[29739.063366] ieee80211 phy0: U iwl4965_verify_bsm Begin verify bsm
[29739.072485] ieee80211 phy0: U iwl4965_verify_bsm BSM bootstrap uCode image OK
[29739.079671] ieee80211 phy0: U iwl4965_load_bsm BSM write complete, poll 0 iterations
[29739.257019] ieee80211 phy0: I iwl_rx_reply_alive Alive ucode status 0x00000001 revision 0x1 0x9
[29739.260964] ieee80211 phy0: I iwl_rx_reply_alive Initialization Alive received.
[29739.260964] ieee80211 phy0: U __iwl_up iwlagn is coming up
[29739.278571] ieee80211 phy0: U iwl_mac_start Start UP work done.
[29739.284509] ieee80211 phy0: U iwlcore_verify_inst_sparse ucode inst image size is 788
[29739.292432] ieee80211 phy0: U iwlcore_verify_inst_sparse ucode inst image size is 10312
[29739.302004] ieee80211 phy0: U iwl_verify_ucode Initialize uCode is good in inst SRAM
[29739.309746] ieee80211 phy0: U iwl4965_hw_get_temperature Running temperature calibration
[29739.317833] ieee80211 phy0: U iwl4965_hw_get_temperature Calib values R[1-3]: -36 13522 -13496 R4: -2726
[29739.327337] ieee80211 phy0: U iwl4965_hw_get_temperature Calibrated temperature: 310K, 37C
[29739.335598] ieee80211 phy0: U iwl4965_init_alive_start Initialization Alive received.
[29739.343477] ieee80211 phy0: U iwl4965_set_ucode_ptrs Runtime uCode pointers are set.
[29739.351283] ieee80211 phy0: I iwl_rx_reply_alive Alive ucode status 0x00000001 revision 0x1 0x0
[29739.355210] ieee80211 phy0: I iwl_rx_reply_alive Runtime Alive received.
[29739.366731] iwlagn 0000:03:00.0: Runtime uCode already alive? Waiting for alive anyway
[29743.284110] iwlagn 0000:03:00.0: START_ALIVE timeout after 4000ms.
[29743.290337] ieee80211 phy0: U iwl_mac_add_interface enter: type 2
[29744.364089] iwlagn 0000:03:00.0: Runtime timeout after 5000ms
[29744.370882] ieee80211 phy0: U iwl_alive_start Runtime Alive received.
[29744.377347] ieee80211 phy0: U iwlcore_verify_inst_sparse ucode inst image size is 788
[29744.385287] ieee80211 phy0: U iwlcore_verify_inst_sparse ucode inst image size is 10312
[29744.393397] ieee80211 phy0: U iwlcore_verify_inst_sparse ucode inst image size is 94720
[29744.415835] ieee80211 phy0: U iwl_verify_ucode Runtime uCode is good in inst SRAM
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>