As per the RZ/G2L users hardware manual (Rev.1.20 Sep, 2022), section 23.3.7 Serial Data Transmission (Asynchronous Mode) it is mentioned that the TE (transmit enable) must be set after setting TIE (transmit interrupt enable) or these 2 bits are set to 1 simultaneously by a single instruction. So set these 2 bits in single instruction.
Fixes: 93bcefd4c6ba ("serial: sh-sci: Fix setting SCSCR_TIE while transferring data") Cc: stable@vger.kernel.org Signed-off-by: Biju Das biju.das.jz@bp.renesas.com --- v3: * New patch moved here from Renesas SCI fixes patch series * Updated commit description * Moved handling of clearing TE bit as separate patch#5. --- drivers/tty/serial/sh-sci.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 15743c2f3d3d..32f5c1f7d697 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -601,6 +601,15 @@ static void sci_start_tx(struct uart_port *port) 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); } } @@ -2600,8 +2609,14 @@ 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)) {
Hi All,
-----Original Message----- From: Biju Das biju.das.jz@bp.renesas.com Sent: Friday, March 31, 2023 12:34 PM To: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Biju Das biju.das.jz@bp.renesas.com; Jiri Slaby jirislaby@kernel.org; Geert Uytterhoeven geert+renesas@glider.be; Yoshinori Sato ysato@users.sourceforge.jp; linux-serial@vger.kernel.org; Prabhakar Mahadev Lad prabhakar.mahadev-lad.rj@bp.renesas.com; linux- renesas-soc@vger.kernel.org; stable@vger.kernel.org Subject: [PATCH v3 3/5] tty: serial: sh-sci: Fix TE setting on SCI IP
As per the RZ/G2L users hardware manual (Rev.1.20 Sep, 2022), section 23.3.7 Serial Data Transmission (Asynchronous Mode) it is mentioned that the TE (transmit enable) must be set after setting TIE (transmit interrupt enable) or these 2 bits are set to 1 simultaneously by a single instruction. So set these 2 bits in single instruction.
Fixes: 93bcefd4c6ba ("serial: sh-sci: Fix setting SCSCR_TIE while transferring data") Cc: stable@vger.kernel.org
I rechecked and the fixes tag is wrong. So, I would like to remove fixes tag for this patch in next version.
Cheers, Biju
Signed-off-by: Biju Das biju.das.jz@bp.renesas.com
v3:
- New patch moved here from Renesas SCI fixes patch series
- Updated commit description
- Moved handling of clearing TE bit as separate patch#5.
drivers/tty/serial/sh-sci.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 15743c2f3d3d..32f5c1f7d697 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -601,6 +601,15 @@ static void sci_start_tx(struct uart_port *port) 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 tostart
* the transmit process.*/if (port->type == PORT_SCI)ctrl |= SCSCR_TE;- serial_port_out(port, SCSCR, ctrl | SCSCR_TIE); }
} @@ -2600,8 +2609,14 @@ 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)) {
-- 2.25.1
linux-stable-mirror@lists.linaro.org
-
Biju Das