Fix broken uart on Win2016 guest.

Obtained from:	Joyent (commit/2bf1a940afbd1382faff159e7c93c72779ca10f4)
MFC after:	3 weeks.
This commit is contained in:
Marcelo Araujo 2019-01-16 03:46:27 +00:00
parent 15b7da10ac
commit 73f6ccd9e7
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=343077

View File

@ -431,6 +431,13 @@ uart_write(struct uart_softc *sc, int offset, uint8_t value)
sc->thre_int_pending = true;
break;
case REG_IER:
/* Assert an interrupt if re-enabling the THRE intr, since we
* always report THRE as active in the status register.
*/
if ((sc->ier & IER_ETXRDY) == 0 &&
(value & IER_ETXRDY) != 0) {
sc->thre_int_pending = true;
}
/*
* Apply mask so that bits 4-7 are 0
* Also enables bits 0-3 only if they're 1