need help about use SPI in interrupt mode. arduino hanged.

[lxbzmy]

I wang use int.0 to chatch data line rising ,and recieve spi data from wizfi210.

I tested this program in loop query mode.It works very good.

But when I chang it to use int0 , and programe hang.T-T.It hanged after spi data send finish.

I can not found where is problem.
This is part of programe

pinMode(WIFI_CS_PIN, OUTPUT);
pinMode(2, INPUT);
SPI.setDataMode(SPI_MODE0);
SPI.setBitOrder(MSBFIRST);
SPI.setClockDivider(SPI_CLOCK_DIV16);
SPI.begin();

wifi chip sync success ful. and

attachInterrupt(0, toSerial, CHANGE);

then :

void loop() {

wdt_reset();
static char tmp;
static unsigned long ms = millis();
//use this to detect serial is live
if (millis() - ms > 5000) {
    Serial.print(".");
    ms = millis();
}

while (Serial.available()) {
    //encs;
    tmp = Serial.read();
    *p++ = tmp;
    if (tmp == '\r') {
        int l = strlen(buf);
        Serial.print(">");
        Serial.print(l);

        for (int i = 0; i < l; i++) {
            wifi_write(buf[i]);
        }
        //get response

        Serial.print('<');
        //clean cache to receive next cmd.
        p = buf;
        memset(buf, '\0', 33);

    }
}
while (digitalRead(WIFI_DATA_PIN)) {
    tmp = wifi_read_byte();
    if ((tmp != SPI_IDLE_CHAR) && (tmp != SPI_INVALID_CHAR_ALL_ZERO)
            && (tmp != SPI_INVALID_CHAR_ALL_ONE)) {
        Serial.print(char(tmp));
    }
}
//decs;

}
void toSerial() {
//detachInterrupt(0);
Serial.print("int0");
/char Msgbuf[68];
memset(Msgbuf, '\0', sizeof(Msgbuf));
Check_OK((byte) Msgbuf, 2000);*/
while (digitalRead(WIFI_DATA_PIN)) {

    tmp = wifi_read_byte();
    if ((tmp != SPI_IDLE_CHAR) && (tmp != SPI_INVALID_CHAR_ALL_ZERO)
            && (tmp != SPI_INVALID_CHAR_ALL_ONE)) {

        Serial.print(char(tmp));
    }
}
Serial.print(".");
//attachInterrupt(0, toSerial, CHANGE);

}

hang as soon as i send AT&V command