Hi Biju,
On Mon, Mar 20, 2023 at 11:53 AM Biju Das biju.das.jz@bp.renesas.com wrote:
For SCI, the TE (transmit enable) must be set after setting TIE (transmit interrupt enable) or in the same instruction to start the transmission. Set TE bit in sci_start_tx() instead of set_termios() for SCI and clear TE bit, if circular buffer is empty in sci_transmit_chars().
Fixes: f9a2adcc9e90 ("arm64: dts: renesas: r9a07g044: Add SCI[0-1] nodes")
That's a DTS patch?
I'm wondering if this got broken accidentally by commit 93bcefd4c6bad4c6 ("serial: sh-sci: Fix setting SCSCR_TIE while transferring data"), which was probably never tested on SCI.
Cc: stable@vger.kernel.org Signed-off-by: Biju Das biju.das.jz@bp.renesas.com
v3:
- New patch
drivers/tty/serial/sh-sci.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index b9cd27451f90..9079a8ea9132 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -597,6 +597,15 @@ static void sci_start_tx(struct uart_port *port) if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) { /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */ ctrl = serial_port_in(port, SCSCR);
/** For SCI, TE (transmit enable) must be set after setting TIE* (transmit interrupt enable) or in the same instruction to start* the transmit process.*/if (port->type == PORT_SCI)ctrl |= SCSCR_TE;serial_port_out(port, SCSCR, ctrl | SCSCR_TIE); }} @@ -835,6 +844,12 @@ static void sci_transmit_chars(struct uart_port *port) c = xmit->buf[xmit->tail]; xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); } else {
if (port->type == PORT_SCI) {ctrl = serial_port_in(port, SCSCR);ctrl &= ~SCSCR_TE;serial_port_out(port, SCSCR, ctrl);return;} break; }@@ -2581,8 +2596,14 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, sci_set_mctrl(port, port->mctrl); }
scr_val |= SCSCR_RE | SCSCR_TE |(s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
/** For SCI, TE (transmit enable) must be set after setting TIE* (transmit interrupt enable) or in the same instruction to* start the transmitting process. So skip setting TE here for SCI.*/if (port->type != PORT_SCI)scr_val |= SCSCR_TE;scr_val |= SCSCR_RE | (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)); serial_port_out(port, SCSCR, scr_val | s->hscif_tot); if ((srr + 1 == 5) && (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
Gr{oetje,eeting}s,
Geert