From: Takatoshi Akiyama <[email protected]>
The SCSCR register access in sci_break_ctl() is not locked. sci_start_tx() and sci_set_termios() changes the SCSCR register, but does not lock sci_port. Therefore, this patch adds lock during register access. Also, remove the log output that leads to a double lock. Signed-off-by: Takatoshi Akiyama <[email protected]> Signed-off-by: Takeshi Kihara <[email protected]> Signed-off-by: Simon Horman <[email protected]> --- This is a patch from the Gen3 3.3.2 BSP. Geert, please consider it for mainline. It appears that the lock is not taken in start_tx() as this is installed as a callback. And all callers of the callback take the lock. --- drivers/tty/serial/sh-sci.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 91e7dddbf72c..f4d705399d25 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1243,8 +1243,11 @@ static void sci_tx_dma_release(struct sci_port *s, bool enable_pio) dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE, DMA_TO_DEVICE); dma_release_channel(chan); - if (enable_pio) + if (enable_pio) { + spin_lock_irqsave(&port->lock, flags); sci_start_tx(port); + spin_unlock_irqrestore(&port->lock, flags); + } } static void sci_submit_rx(struct sci_port *s) @@ -1934,6 +1937,7 @@ static void sci_enable_ms(struct uart_port *port) static void sci_break_ctl(struct uart_port *port, int break_state) { unsigned short scscr, scsptr; + unsigned long flags; /* check wheter the port has SCSPTR */ if (!sci_getreg(port, SCSPTR)->size) { @@ -1944,6 +1948,7 @@ static void sci_break_ctl(struct uart_port *port, int break_state) return; } + spin_lock_irqsave(&port->lock, flags); scsptr = serial_port_in(port, SCSPTR); scscr = serial_port_in(port, SCSCR); @@ -1957,6 +1962,7 @@ static void sci_break_ctl(struct uart_port *port, int break_state) serial_port_out(port, SCSPTR, scsptr); serial_port_out(port, SCSCR, scscr); + spin_unlock_irqrestore(&port->lock, flags); } static int sci_startup(struct uart_port *port) @@ -2168,6 +2174,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, int min_err = INT_MAX, err; unsigned long max_freq = 0; int best_clk = -1; + unsigned long flags; if ((termios->c_cflag & CSIZE) == CS7) smr_val |= SCSMR_CHR; @@ -2277,6 +2284,8 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, serial_port_out(port, SCCKS, sccks); } + spin_lock_irqsave(&port->lock, flags); + sci_reset(port); uart_update_timeout(port, termios->c_cflag, baud); @@ -2294,9 +2303,6 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, case 27: smr_val |= SCSMR_SRC_27; break; } smr_val |= cks; - dev_dbg(port->dev, - "SCR 0x%x SMR 0x%x BRR %u CKS 0x%x DL %u SRR %u\n", - scr_val, smr_val, brr, sccks, dl, srr); serial_port_out(port, SCSCR, scr_val); serial_port_out(port, SCSMR, smr_val); serial_port_out(port, SCBRR, brr); @@ -2310,7 +2316,6 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0); smr_val |= serial_port_in(port, SCSMR) & (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS); - dev_dbg(port->dev, "SCR 0x%x SMR 0x%x\n", scr_val, smr_val); serial_port_out(port, SCSCR, scr_val); serial_port_out(port, SCSMR, smr_val); } @@ -2342,7 +2347,6 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, } scr_val |= s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0); - dev_dbg(port->dev, "SCSCR 0x%x\n", scr_val); serial_port_out(port, SCSCR, scr_val); if ((srr + 1 == 5) && (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) { @@ -2391,8 +2395,6 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, bits++; s->rx_timeout = DIV_ROUND_UP((s->buf_len_rx * 2 * bits * HZ) / (baud / 10), 10); - dev_dbg(port->dev, "DMA Rx t-out %ums, tty t-out %u jiffies\n", - s->rx_timeout * 1000 / HZ, port->timeout); if (s->rx_timeout < msecs_to_jiffies(20)) s->rx_timeout = msecs_to_jiffies(20); } @@ -2401,6 +2403,8 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, if ((termios->c_cflag & CREAD) != 0) sci_start_rx(port); + spin_unlock_irqrestore(&port->lock, flags); + sci_port_disable(s); if (UART_ENABLE_MS(port, termios->c_cflag)) -- 2.7.0.rc3.207.g0ac5344
