The various SCI implementations use 3 different methods to signal
overrun errors:
- Bit SCI_ORER in register SCxSR on SCI,
- Bit SCIFA_ORER in register SCxSR on SCIFA and SCIFB, and SCIF on
SH7705/SH7720/SH7721,
- Bit SCLSR_ORER in (optional!) register SCLSR on (H)SCIF.
However:
1. sci_handle_fifo_overrun()
a. handles (H)SCIF and SCIFA/SCIFB only,
b. treats SCIF on SH7705/SH7720/SH7721 incorrectly,
2. sci_mpxed_interrupt()
a. treats SCIF on SH7705/SH7720/SH7721 incorrectly,
b. ignores that not all SCIFs have the SCLSR register, causing
"Invalid register access" WARN()ings.
To fix the above:
1. Determine and store the correct register enum during
initialization,
2. Replace the duplicated buggy switch statements by using the stored
register enum,
3. Add the missing existence check to sci_mpxed_interrupt().
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
drivers/tty/serial/sh-sci.c | 40 +++++++++++++++-------------------------
1 file changed, 15 insertions(+), 25 deletions(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 83c46e1581590401..b636c53a1e5b3866 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -81,6 +81,7 @@ struct sci_port {
/* Platform configuration */
struct plat_sci_port *cfg;
+ unsigned int overrun_reg;
unsigned int overrun_mask;
unsigned int error_mask;
unsigned int sampling_rate;
@@ -866,30 +867,17 @@ static int sci_handle_fifo_overrun(struct uart_port *port)
struct tty_port *tport = &port->state->port;
struct sci_port *s = to_sci_port(port);
struct plat_sci_reg *reg;
- int copied = 0, offset;
+ int copied = 0;
u16 status;
- switch (port->type) {
- case PORT_SCIF:
- case PORT_HSCIF:
- offset = SCLSR;
- break;
- case PORT_SCIFA:
- case PORT_SCIFB:
- offset = SCxSR;
- break;
- default:
- return 0;
- }
-
- reg = sci_getreg(port, offset);
+ reg = sci_getreg(port, s->overrun_reg);
if (!reg->size)
return 0;
- status = serial_port_in(port, offset);
+ status = serial_port_in(port, s->overrun_reg);
if (status & s->overrun_mask) {
status &= ~s->overrun_mask;
- serial_port_out(port, offset, status);
+ serial_port_out(port, s->overrun_reg, status);
port->icount.overrun++;
@@ -1041,15 +1029,11 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
ssr_status = serial_port_in(port, SCxSR);
scr_status = serial_port_in(port, SCSCR);
- switch (port->type) {
- case PORT_SCIF:
- case PORT_HSCIF:
- orer_status = serial_port_in(port, SCLSR);
- break;
- case PORT_SCIFA:
- case PORT_SCIFB:
+ if (s->overrun_reg == SCxSR)
orer_status = ssr_status;
- break;
+ else {
+ if (sci_getreg(port, s->overrun_reg)->size)
+ orer_status = serial_port_in(port, s->overrun_reg);
}
err_enabled = scr_status & port_rx_irq_mask(port);
@@ -2254,31 +2238,37 @@ static int sci_init_single(struct platform_device *dev,
switch (p->type) {
case PORT_SCIFB:
port->fifosize = 256;
+ sci_port->overrun_reg = SCxSR;
sci_port->overrun_mask = SCIFA_ORER;
sampling_rate = 16;
break;
case PORT_HSCIF:
port->fifosize = 128;
sampling_rate = 0;
+ sci_port->overrun_reg = SCLSR;
sci_port->overrun_mask = SCLSR_ORER;
break;
case PORT_SCIFA:
port->fifosize = 64;
+ sci_port->overrun_reg = SCxSR;
sci_port->overrun_mask = SCIFA_ORER;
sampling_rate = 16;
break;
case PORT_SCIF:
port->fifosize = 16;
if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) {
+ sci_port->overrun_reg = SCxSR;
sci_port->overrun_mask = SCIFA_ORER;
sampling_rate = 16;
} else {
+ sci_port->overrun_reg = SCLSR;
sci_port->overrun_mask = SCLSR_ORER;
sampling_rate = 32;
}
break;
default:
port->fifosize = 1;
+ sci_port->overrun_reg = SCxSR;
sci_port->overrun_mask = SCI_ORER;
sampling_rate = 32;
break;
--
1.9.1
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