serial: sh-sci: SCIFA/B RX FIFO software timeout (03940376) · Commits · 戴 / test

drivers/tty/serial/sh-sci.c

+68 −33

Original line number	Diff line number	Diff line
		@@ -148,7 +148,10 @@ struct sci_port {
		struct timer_list rx_timer;
		unsigned int rx_timeout;
		#endif
		unsigned int rx_frame;
		int rx_trigger;
		struct timer_list rx_fifo_timer;
		int rx_fifo_timeout;

		bool has_rtscts;
		bool autorts;
		@@ -1034,6 +1037,24 @@ static int scif_set_rtrg(struct uart_port *port, int rx_trig)
		return rx_trig;
		}

		static int scif_rtrg_enabled(struct uart_port *port)
		{
		if (sci_getreg(port, HSRTRGR)->size)
		return serial_port_in(port, HSRTRGR) != 0;
		else
		return (serial_port_in(port, SCFCR) &
		(SCFCR_RTRG0 \| SCFCR_RTRG1)) != 0;
		}

		static void rx_fifo_timer_fn(unsigned long arg)
		{
		struct sci_port s = (struct sci_port )arg;
		struct uart_port *port = &s->port;

		dev_dbg(port->dev, "Rx timed out\n");
		scif_set_rtrg(port, 1);
		}

		#ifdef CONFIG_SERIAL_SH_SCI_DMA
		static void sci_dma_tx_complete(void *arg)
		{
		@@ -1473,10 +1494,10 @@ static inline void sci_free_dma(struct uart_port *port)

		static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
		{
		#ifdef CONFIG_SERIAL_SH_SCI_DMA
		struct uart_port *port = ptr;
		struct sci_port *s = to_sci_port(port);

		#ifdef CONFIG_SERIAL_SH_SCI_DMA
		if (s->chan_rx) {
		u16 scr = serial_port_in(port, SCSCR);
		u16 ssr = serial_port_in(port, SCxSR);
		@@ -1501,6 +1522,14 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
		}
		#endif

		if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
		if (!scif_rtrg_enabled(port))
		scif_set_rtrg(port, s->rx_trigger);

		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
		s->rx_frame * s->rx_fifo_timeout, 1000));
		}

		/* I think sci_receive_chars has to be called irrespective
		* of whether the I_IXOFF is set, otherwise, how is the interrupt
		* to be disabled?
		@@ -2084,14 +2113,21 @@ static void sci_reset(struct uart_port *port)
		serial_port_out(port, SCLSR, status);
		}

		if (s->rx_trigger > 1)
		if (s->rx_trigger > 1) {
		if (s->rx_fifo_timeout) {
		scif_set_rtrg(port, 1);
		setup_timer(&s->rx_fifo_timer, rx_fifo_timer_fn,
		(unsigned long)s);
		} else {
		scif_set_rtrg(port, s->rx_trigger);
		}
		}
		}

		static void sci_set_termios(struct uart_port port, struct ktermios termios,
		struct ktermios *old)
		{
		unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i;
		unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
		unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
		unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
		struct sci_port *s = to_sci_port(port);
		@@ -2287,7 +2323,6 @@ done:
		udelay(DIV_ROUND_UP(10 * 1000000, baud));
		}

		#ifdef CONFIG_SERIAL_SH_SCI_DMA
		/*
		* Calculate delay for 2 DMA buffers (4 FIFO).
		* See serial_core.c::uart_update_timeout().
		@@ -2298,9 +2333,6 @@ done:
		* value obtained by this formula is too small. Therefore, if the value
		* is smaller than 20ms, use 20ms as the timeout value for DMA.
		*/
		if (s->chan_rx) {
		unsigned int bits;

		/* byte size and parity */
		switch (termios->c_cflag & CSIZE) {
		case CS5:
		@@ -2321,13 +2353,14 @@ done:
		bits++;
		if (termios->c_cflag & PARENB)
		bits++;
		s->rx_timeout = DIV_ROUND_UP((s->buf_len_rx * 2 * bits * HZ) /
		(baud / 10), 10);

		s->rx_frame = (100 * bits * HZ) / (baud / 10);
		#ifdef CONFIG_SERIAL_SH_SCI_DMA
		s->rx_timeout = DIV_ROUND_UP(s->buf_len_rx * 2 * s->rx_frame, 1000);
		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);
		}
		#endif

		if ((termios->c_cflag & CREAD) != 0)
		@@ -2642,6 +2675,8 @@ static int sci_init_single(struct platform_device *dev,
		break;
		}

		sci_port->rx_fifo_timeout = 0;

		/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
		* match the SoC datasheet, this should be investigated. Let platform
		* data override the sampling rate for now.

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