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serial: sh-sci: Use the correct register for overrun checks

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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@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Geert Uytterhoeven 2015-04-30 18:21:32 +02:00 committed by Greg Kroah-Hartman
parent 75c249fd7c
commit 2e0842a154
1 changed files with 15 additions and 25 deletions
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40
drivers/tty/serial/sh-sci.c
View File

@ -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;