PORT_AUTO_NEG_SYM_PAUSE
if (ctrl & PORT_AUTO_NEG_SYM_PAUSE)
data &= ~(PORT_AUTO_NEG_SYM_PAUSE |
data |= PORT_AUTO_NEG_SYM_PAUSE;
(PORT_AUTO_NEG_ASYM_PAUSE | PORT_AUTO_NEG_SYM_PAUSE)
ctrl &= ~PORT_AUTO_NEG_SYM_PAUSE;
ctrl |= PORT_AUTO_NEG_SYM_PAUSE;