From 4431a1c34d1a9c36b7251217a2783d09ee1a7ac3 Mon Sep 17 00:00:00 2001 From: jiaguo Date: Thu, 13 Mar 2014 18:49:14 +0800 Subject: Wi-Fi HAL: fix supplicant start failed issue init.svc.*(hostapd, p2p_supplicant) properties are set when starting STA or uAP via Wi-Fi HAL, after sending ctrl.start command to property_service, thread called wifi_start_supplicant will yield cpu for android init process to get scheduled, then init.svc.* status is read to check if supplicant status is running there is a chance that after scheld_yield returned, init is not scheduled, serial value is not updated, __system_property_read got the "stopped" status, then init is scheduled to update service status after that back to this loop in Wi-Fi HAL, serial is updated, but status is not reread, still used "stopped", then Wi-Fi HAL will report supplicant start failed as the following schedule sequence: process A(WifiStateMachine) process B(init) 1. ctl.start 2. scheld_yield 3. __system_proerty_read /*serial1, value1*/ 4. __system_property_update /*serial2, value2*/ 5. serial1 != serial2 6. value1 == "stopped" So after sched_yield, first check if serial is updated, then read service status Change-Id: I5181e0d4504c525832c033b9a35bd58ec63e1de8 Signed-off-by: jiaguo --- wifi/wifi.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'wifi') diff --git a/wifi/wifi.c b/wifi/wifi.c index f11c1ab..25a6fb7 100644 --- a/wifi/wifi.c +++ b/wifi/wifi.c @@ -556,12 +556,16 @@ int wifi_start_supplicant(int p2p_supported) pi = __system_property_find(supplicant_prop_name); } if (pi != NULL) { - __system_property_read(pi, NULL, supp_status); - if (strcmp(supp_status, "running") == 0) { - return 0; - } else if (__system_property_serial(pi) != serial && - strcmp(supp_status, "stopped") == 0) { - return -1; + /* + * property serial updated means that init process is scheduled + * after we sched_yield, further property status checking is based on this */ + if (__system_property_serial(pi) != serial) { + __system_property_read(pi, NULL, supp_status); + if (strcmp(supp_status, "running") == 0) { + return 0; + } else if (strcmp(supp_status, "stopped") == 0) { + return -1; + } } } #else -- cgit v1.1