TTY/Serial driver fixes for 6.10-rc4

Here are some small tty and serial driver fixes that resolve som
 reported problems.  Included in here are:
   - n_tty lookahead buffer bugfix
   - WARN_ON() removal where it was not needed
   - 8250_dw driver bugfixes
   - 8250_pxa bugfix
   - sc16is7xx Kconfig fixes for reported build issues
 
 All of these have been in linux-next for over a week with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are some small tty and serial driver fixes that resolve som
  reported problems. Included in here are:

   - n_tty lookahead buffer bugfix

   - WARN_ON() removal where it was not needed

   - 8250_dw driver bugfixes

   - 8250_pxa bugfix

   - sc16is7xx Kconfig fixes for reported build issues

  All of these have been in linux-next for over a week with no reported
  problems"

* tag 'tty-6.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: drop debugging WARN_ON_ONCE() from uart_write()
  serial: sc16is7xx: re-add Kconfig SPI or I2C dependency
  serial: sc16is7xx: rename Kconfig CONFIG_SERIAL_SC16IS7XX_CORE
  serial: port: Don't block system suspend even if bytes are left to xmit
  serial: 8250_pxa: Configure tx_loadsz to match FIFO IRQ level
  serial: 8250_dw: Revert "Move definitions to the shared header"
  serial: 8250_dw: Don't use struct dw8250_data outside of 8250_dw
  tty: n_tty: Fix buffer offsets when lookahead is used

drivers/tty/n_tty.c

@@ -1619,15 +1619,25 @@ static void __receive_buf(struct tty_struct *tty, const u8 *cp, const u8 *fp,
 	else if (ldata->raw || (L_EXTPROC(tty) && !preops))
 		n_tty_receive_buf_raw(tty, cp, fp, count);
 	else if (tty->closing && !L_EXTPROC(tty)) {
-		if (la_count > 0)
+		if (la_count > 0) {
 			n_tty_receive_buf_closing(tty, cp, fp, la_count, true);
-		if (count > la_count)
-			n_tty_receive_buf_closing(tty, cp, fp, count - la_count, false);
+			cp += la_count;
+			if (fp)
+				fp += la_count;
+			count -= la_count;
+		}
+		if (count > 0)
+			n_tty_receive_buf_closing(tty, cp, fp, count, false);
 	} else {
-		if (la_count > 0)
+		if (la_count > 0) {
 			n_tty_receive_buf_standard(tty, cp, fp, la_count, true);
-		if (count > la_count)
-			n_tty_receive_buf_standard(tty, cp, fp, count - la_count, false);
+			cp += la_count;
+			if (fp)
+				fp += la_count;
+			count -= la_count;
+		}
+		if (count > 0)
+			n_tty_receive_buf_standard(tty, cp, fp, count, false);
 
 		flush_echoes(tty);
 		if (tty->ops->flush_chars)

drivers/tty/serial/8250/8250_dw.c

@@ -55,6 +55,34 @@
 #define DW_UART_QUIRK_SKIP_SET_RATE	BIT(2)
 #define DW_UART_QUIRK_IS_DMA_FC		BIT(3)
 #define DW_UART_QUIRK_APMC0D08		BIT(4)
+#define DW_UART_QUIRK_CPR_VALUE		BIT(5)
+
+struct dw8250_platform_data {
+	u8 usr_reg;
+	u32 cpr_value;
+	unsigned int quirks;
+};
+
+struct dw8250_data {
+	struct dw8250_port_data	data;
+	const struct dw8250_platform_data *pdata;
+
+	int			msr_mask_on;
+	int			msr_mask_off;
+	struct clk		*clk;
+	struct clk		*pclk;
+	struct notifier_block	clk_notifier;
+	struct work_struct	clk_work;
+	struct reset_control	*rst;
+
+	unsigned int		skip_autocfg:1;
+	unsigned int		uart_16550_compatible:1;
+};
+
+static inline struct dw8250_data *to_dw8250_data(struct dw8250_port_data *data)
+{
+	return container_of(data, struct dw8250_data, data);
+}
 
 static inline struct dw8250_data *clk_to_dw8250_data(struct notifier_block *nb)
 {
@@ -432,6 +460,10 @@ static void dw8250_prepare_rx_dma(struct uart_8250_port *p)
 static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 {
 	unsigned int quirks = data->pdata ? data->pdata->quirks : 0;
+	u32 cpr_value = data->pdata ? data->pdata->cpr_value : 0;
+
+	if (quirks & DW_UART_QUIRK_CPR_VALUE)
+		data->data.cpr_value = cpr_value;
 
 #ifdef CONFIG_64BIT
 	if (quirks & DW_UART_QUIRK_OCTEON) {
@@ -714,8 +746,8 @@ static const struct dw8250_platform_data dw8250_armada_38x_data = {
 
 static const struct dw8250_platform_data dw8250_renesas_rzn1_data = {
 	.usr_reg = DW_UART_USR,
-	.cpr_val = 0x00012f32,
-	.quirks = DW_UART_QUIRK_IS_DMA_FC,
+	.cpr_value = 0x00012f32,
+	.quirks = DW_UART_QUIRK_CPR_VALUE | DW_UART_QUIRK_IS_DMA_FC,
 };
 
 static const struct dw8250_platform_data dw8250_starfive_jh7100_data = {

drivers/tty/serial/8250/8250_dwlib.c

@@ -242,7 +242,6 @@ static const struct serial_rs485 dw8250_rs485_supported = {
 void dw8250_setup_port(struct uart_port *p)
 {
 	struct dw8250_port_data *pd = p->private_data;
-	struct dw8250_data *data = to_dw8250_data(pd);
 	struct uart_8250_port *up = up_to_u8250p(p);
 	u32 reg, old_dlf;
 
@@ -278,7 +277,7 @@ void dw8250_setup_port(struct uart_port *p)
 
 	reg = dw8250_readl_ext(p, DW_UART_CPR);
 	if (!reg) {
-		reg = data->pdata->cpr_val;
+		reg = pd->cpr_value;
 		dev_dbg(p->dev, "CPR is not available, using 0x%08x instead\n", reg);
 	}
 	if (!reg)

drivers/tty/serial/8250/8250_dwlib.h

@@ -2,15 +2,10 @@
 /* Synopsys DesignWare 8250 library header file. */
 
 #include <linux/io.h>
-#include <linux/notifier.h>
 #include <linux/types.h>
-#include <linux/workqueue.h>
 
 #include "8250.h"
 
-struct clk;
-struct reset_control;
-
 struct dw8250_port_data {
 	/* Port properties */
 	int			line;
@@ -19,42 +14,16 @@ struct dw8250_port_data {
 	struct uart_8250_dma	dma;
 
 	/* Hardware configuration */
+	u32			cpr_value;
 	u8			dlf_size;
 
 	/* RS485 variables */
 	bool			hw_rs485_support;
 };
 
-struct dw8250_platform_data {
-	u8 usr_reg;
-	u32 cpr_val;
-	unsigned int quirks;
-};
-
-struct dw8250_data {
-	struct dw8250_port_data	data;
-	const struct dw8250_platform_data *pdata;
-
-	int			msr_mask_on;
-	int			msr_mask_off;
-	struct clk		*clk;
-	struct clk		*pclk;
-	struct notifier_block	clk_notifier;
-	struct work_struct	clk_work;
-	struct reset_control	*rst;
-
-	unsigned int		skip_autocfg:1;
-	unsigned int		uart_16550_compatible:1;
-};
-
 void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, const struct ktermios *old);
 void dw8250_setup_port(struct uart_port *p);
 
-static inline struct dw8250_data *to_dw8250_data(struct dw8250_port_data *data)
-{
-	return container_of(data, struct dw8250_data, data);
-}
-
 static inline u32 dw8250_readl_ext(struct uart_port *p, int offset)
 {
 	if (p->iotype == UPIO_MEM32BE)

drivers/tty/serial/8250/8250_pxa.c

@@ -125,6 +125,7 @@ static int serial_pxa_probe(struct platform_device *pdev)
 	uart.port.iotype = UPIO_MEM32;
 	uart.port.regshift = 2;
 	uart.port.fifosize = 64;
+	uart.tx_loadsz = 32;
 	uart.dl_write = serial_pxa_dl_write;
 
 	ret = serial8250_register_8250_port(&uart);

drivers/tty/serial/Kconfig

@@ -1023,8 +1023,9 @@ config SERIAL_SCCNXP_CONSOLE
 	help
 	  Support for console on SCCNXP serial ports.
 
-config SERIAL_SC16IS7XX_CORE
+config SERIAL_SC16IS7XX
 	tristate "NXP SC16IS7xx UART support"
+	depends on SPI_MASTER || I2C
 	select SERIAL_CORE
 	select SERIAL_SC16IS7XX_SPI if SPI_MASTER
 	select SERIAL_SC16IS7XX_I2C if I2C

drivers/tty/serial/Makefile

@@ -75,7 +75,7 @@ obj-$(CONFIG_SERIAL_SA1100)		+= sa1100.o
 obj-$(CONFIG_SERIAL_SAMSUNG)		+= samsung_tty.o
 obj-$(CONFIG_SERIAL_SB1250_DUART)	+= sb1250-duart.o
 obj-$(CONFIG_SERIAL_SCCNXP)		+= sccnxp.o
-obj-$(CONFIG_SERIAL_SC16IS7XX_CORE)	+= sc16is7xx.o
+obj-$(CONFIG_SERIAL_SC16IS7XX)		+= sc16is7xx.o
 obj-$(CONFIG_SERIAL_SC16IS7XX_SPI)	+= sc16is7xx_spi.o
 obj-$(CONFIG_SERIAL_SC16IS7XX_I2C)	+= sc16is7xx_i2c.o
 obj-$(CONFIG_SERIAL_SH_SCI)		+= sh-sci.o

drivers/tty/serial/serial_core.c

@@ -622,7 +622,7 @@ static ssize_t uart_write(struct tty_struct *tty, const u8 *buf, size_t count)
 		return -EL3HLT;
 
 	port = uart_port_lock(state, flags);
-	if (WARN_ON_ONCE(!state->port.xmit_buf)) {
+	if (!state->port.xmit_buf) {
 		uart_port_unlock(port, flags);
 		return 0;
 	}

drivers/tty/serial/serial_port.c

@@ -64,6 +64,13 @@ static int serial_port_runtime_suspend(struct device *dev)
 	if (port->flags & UPF_DEAD)
 		return 0;
 
+	/*
+	 * Nothing to do on pm_runtime_force_suspend(), see
+	 * DEFINE_RUNTIME_DEV_PM_OPS.
+	 */
+	if (!pm_runtime_enabled(dev))
+		return 0;
+
 	uart_port_lock_irqsave(port, &flags);
 	if (!port_dev->tx_enabled) {
 		uart_port_unlock_irqrestore(port, flags);