Re: [PATCH v9 2/2] tty/serial: Add Spreadtrum sc9836-uart driver support

Hi Chunyan Zhang,

On Wed, Jan 28, 2015 at 10:47:41AM +0800, Chunyan Zhang wrote:
[...]

+static inline void sprd_rx(struct uart_port *port)
+{
+	struct tty_port *tty = &port->state->port;
+	unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
+
+	while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
+		lsr = serial_in(port, SPRD_LSR);
+		ch = serial_in(port, SPRD_RXD);
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE |
+			SPRD_LSR_FE | SPRD_LSR_OE))
+			if (handle_lsr_errors(port, &lsr, &flag))
+				continue;
+		if (uart_handle_sysrq_char(port, ch))
+			continue;

My comment[1] on a previous version of this patch still stands. 
uart_handle_sysrq_char is a NOP when SUPPORT_SYSRQ is not defined.

+
+		uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
+	}
+
+	tty_flip_buffer_push(tty);
+}

[...]

+static void sprd_console_write(struct console *co, const char *s,
+				      unsigned int count)
+{
+	struct uart_port *port = &sprd_port[co->index]->port;
+	int locked = 1;
+	unsigned long flags;
+
+	if (port->sysrq)
+		locked = 0;

The sysrq field of struct uart_port is only defined when 
CONFIG_SERIAL_CORE_CONSOLE or SUPPORT_SYSRQ are defined. You should #ifdef 
this part accordingly to avoid build breakage.

+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	uart_console_write(port, s, count, sprd_console_putchar);
+
+	/* wait for transmitter to become empty */
+	wait_for_xmitr(port);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}

[1]
	http://article.gmane.org/gmane.linux.drivers.devicetree/106483

baruch

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