Generate an interrupt if the tx buffer is empty and the tx empty interrupt
is enabled. This fixes a problem seen when running a Linux image since
Linux commit 55c3cb1358e ("serial: imx: remove unneeded imx_transmit_buffer()
from imx_start_tx()"). Linux now waits for the tx empty interrupt before
starting to send data, causing transmit stalls until there is an interrupt
for another reason.
Signed-off-by: Guenter Roeck <li...@roeck-us.net>
---
hw/char/imx_serial.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c
index f3fbc77..8dc791d 100644
--- a/hw/char/imx_serial.c
+++ b/hw/char/imx_serial.c
@@ -145,7 +145,9 @@ static void imx_update(IMXSerialState *s)
uint32_t flags;
flags = (s->usr1 & s->ucr1) & (USR1_TRDY|USR1_RRDY);
- if (!(s->ucr1 & UCR1_TXMPTYEN)) {
+ if (s->ucr1 & UCR1_TXMPTYEN) {
+ flags |= (s->uts1 & UTS1_TXEMPTY);
+ } else {
flags &= ~USR1_TRDY;
}
--
2.1.4
