TTY/Serial fixes for 5.14-rc5

Here are some small tty/serial driver fixes for 5.14-rc5 to resolve a
 number of reported problems.
 
 They include:
 	- mips serial driver fixes
 	- 8250 driver fixes for reported problems
 	- fsl_lpuart driver fixes
 	- other tiny driver fixes
 
 All have been in linux-next for a while with no reported problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial fixes from Greg KH:
 "Here are some small tty/serial driver fixes for 5.14-rc5 to resolve a
  number of reported problems.

  They include:

   - mips serial driver fixes

   - 8250 driver fixes for reported problems

   - fsl_lpuart driver fixes

   - other tiny driver fixes

  All have been in linux-next for a while with no reported problems"

* tag 'tty-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250_pci: Avoid irq sharing for MSI(-X) interrupts.
  serial: 8250_mtk: fix uart corruption issue when rx power off
  tty: serial: fsl_lpuart: fix the wrong return value in lpuart32_get_mctrl
  serial: 8250_pci: Enumerate Elkhart Lake UARTs via dedicated driver
  serial: 8250: fix handle_irq locking
  serial: tegra: Only print FIFO error message when an error occurs
  MIPS: Malta: Do not byte-swap accesses to the CBUS UART
  serial: 8250: Mask out floating 16/32-bit bus bits
  serial: max310x: Unprepare and disable clock in error path

arch/mips/mti-malta/malta-platform.c

@@ -48,7 +48,8 @@ static struct plat_serial8250_port uart8250_data[] = {
 		.mapbase	= 0x1f000900,	/* The CBUS UART */
 		.irq		= MIPS_CPU_IRQ_BASE + MIPSCPU_INT_MB2,
 		.uartclk	= 3686400,	/* Twice the usual clk! */
-		.iotype		= UPIO_MEM32,
+		.iotype		= IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
+				  UPIO_MEM32BE : UPIO_MEM32,
 		.flags		= CBUS_UART_FLAGS,
 		.regshift	= 3,
 	},

drivers/tty/serial/8250/8250_aspeed_vuart.c

@@ -329,6 +329,7 @@ static int aspeed_vuart_handle_irq(struct uart_port *port)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned int iir, lsr;
+	unsigned long flags;
 	unsigned int space, count;
 
 	iir = serial_port_in(port, UART_IIR);
@@ -336,7 +337,7 @@ static int aspeed_vuart_handle_irq(struct uart_port *port)
 	if (iir & UART_IIR_NO_INT)
 		return 0;
 
-	spin_lock(&port->lock);
+	spin_lock_irqsave(&port->lock, flags);
 
 	lsr = serial_port_in(port, UART_LSR);
 
@@ -370,7 +371,7 @@ static int aspeed_vuart_handle_irq(struct uart_port *port)
 	if (lsr & UART_LSR_THRE)
 		serial8250_tx_chars(up);
 
-	uart_unlock_and_check_sysrq(port);
+	uart_unlock_and_check_sysrq_irqrestore(port, flags);
 
 	return 1;
 }

drivers/tty/serial/8250/8250_fsl.c

@@ -30,10 +30,11 @@ struct fsl8250_data {
 int fsl8250_handle_irq(struct uart_port *port)
 {
 	unsigned char lsr, orig_lsr;
+	unsigned long flags;
 	unsigned int iir;
 	struct uart_8250_port *up = up_to_u8250p(port);
 
-	spin_lock(&up->port.lock);
+	spin_lock_irqsave(&up->port.lock, flags);
 
 	iir = port->serial_in(port, UART_IIR);
 	if (iir & UART_IIR_NO_INT) {
@@ -82,7 +83,7 @@ int fsl8250_handle_irq(struct uart_port *port)
 
 	up->lsr_saved_flags = orig_lsr;
 
-	uart_unlock_and_check_sysrq(&up->port);
+	uart_unlock_and_check_sysrq_irqrestore(&up->port, flags);
 
 	return 1;
 }

drivers/tty/serial/8250/8250_mtk.c

@@ -93,10 +93,13 @@ static void mtk8250_dma_rx_complete(void *param)
 	struct dma_tx_state state;
 	int copied, total, cnt;
 	unsigned char *ptr;
+	unsigned long flags;
 
 	if (data->rx_status == DMA_RX_SHUTDOWN)
 		return;
 
+	spin_lock_irqsave(&up->port.lock, flags);
+
 	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
 	total = dma->rx_size - state.residue;
 	cnt = total;
@@ -120,6 +123,8 @@ static void mtk8250_dma_rx_complete(void *param)
 	tty_flip_buffer_push(tty_port);
 
 	mtk8250_rx_dma(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static void mtk8250_rx_dma(struct uart_8250_port *up)

drivers/tty/serial/8250/8250_pci.c

@@ -3836,6 +3836,12 @@ static const struct pci_device_id blacklist[] = {
 	{ PCI_VDEVICE(INTEL, 0x0f0c), },
 	{ PCI_VDEVICE(INTEL, 0x228a), },
 	{ PCI_VDEVICE(INTEL, 0x228c), },
+	{ PCI_VDEVICE(INTEL, 0x4b96), },
+	{ PCI_VDEVICE(INTEL, 0x4b97), },
+	{ PCI_VDEVICE(INTEL, 0x4b98), },
+	{ PCI_VDEVICE(INTEL, 0x4b99), },
+	{ PCI_VDEVICE(INTEL, 0x4b9a), },
+	{ PCI_VDEVICE(INTEL, 0x4b9b), },
 	{ PCI_VDEVICE(INTEL, 0x9ce3), },
 	{ PCI_VDEVICE(INTEL, 0x9ce4), },
 
@@ -3996,6 +4002,7 @@ pciserial_init_ports(struct pci_dev *dev, const struct pciserial_board *board)
 		if (pci_match_id(pci_use_msi, dev)) {
 			dev_dbg(&dev->dev, "Using MSI(-X) interrupts\n");
 			pci_set_master(dev);
+			uart.port.flags &= ~UPF_SHARE_IRQ;
 			rc = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_ALL_TYPES);
 		} else {
 			dev_dbg(&dev->dev, "Using legacy interrupts\n");

drivers/tty/serial/8250/8250_port.c

@@ -311,7 +311,11 @@ static const struct serial8250_config uart_config[] = {
 /* Uart divisor latch read */
 static int default_serial_dl_read(struct uart_8250_port *up)
 {
-	return serial_in(up, UART_DLL) | serial_in(up, UART_DLM) << 8;
+	/* Assign these in pieces to truncate any bits above 7.  */
+	unsigned char dll = serial_in(up, UART_DLL);
+	unsigned char dlm = serial_in(up, UART_DLM);
+
+	return dll | dlm << 8;
 }
 
 /* Uart divisor latch write */
@@ -1297,9 +1301,11 @@ static void autoconfig(struct uart_8250_port *up)
 	serial_out(up, UART_LCR, 0);
 
 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
-	scratch = serial_in(up, UART_IIR) >> 6;
 
-	switch (scratch) {
+	/* Assign this as it is to truncate any bits above 7.  */
+	scratch = serial_in(up, UART_IIR);
+
+	switch (scratch >> 6) {
 	case 0:
 		autoconfig_8250(up);
 		break;
@@ -1893,11 +1899,12 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 	unsigned char status;
 	struct uart_8250_port *up = up_to_u8250p(port);
 	bool skip_rx = false;
+	unsigned long flags;
 
 	if (iir & UART_IIR_NO_INT)
 		return 0;
 
-	spin_lock(&port->lock);
+	spin_lock_irqsave(&port->lock, flags);
 
 	status = serial_port_in(port, UART_LSR);
 
@@ -1923,7 +1930,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 		(up->ier & UART_IER_THRI))
 		serial8250_tx_chars(up);
 
-	uart_unlock_and_check_sysrq(port);
+	uart_unlock_and_check_sysrq_irqrestore(port, flags);
 
 	return 1;
 }

drivers/tty/serial/fsl_lpuart.c

@@ -1415,7 +1415,7 @@ static unsigned int lpuart_get_mctrl(struct uart_port *port)
 
 static unsigned int lpuart32_get_mctrl(struct uart_port *port)
 {
-	unsigned int mctrl = 0;
+	unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
 	u32 reg;
 
 	reg = lpuart32_read(port, UARTCTRL);

drivers/tty/serial/max310x.c

@@ -1293,7 +1293,8 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty
 		freq = uartclk;
 	if (freq == 0) {
 		dev_err(dev, "Cannot get clock rate\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out_clk;
 	}
 
 	if (xtal) {

drivers/tty/serial/serial-tegra.c

@@ -1045,9 +1045,11 @@ static int tegra_uart_hw_init(struct tegra_uart_port *tup)
 
 	if (tup->cdata->fifo_mode_enable_status) {
 		ret = tegra_uart_wait_fifo_mode_enabled(tup);
-		dev_err(tup->uport.dev, "FIFO mode not enabled\n");
-		if (ret < 0)
+		if (ret < 0) {
+			dev_err(tup->uport.dev,
+				"Failed to enable FIFO mode: %d\n", ret);
 			return ret;
+		}
 	} else {
 		/*
 		 * For all tegra devices (up to t210), there is a hardware

include/linux/serial_core.h

@@ -518,6 +518,25 @@ static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
 	if (sysrq_ch)
 		handle_sysrq(sysrq_ch);
 }
+
+static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
+		unsigned long flags)
+{
+	int sysrq_ch;
+
+	if (!port->has_sysrq) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		return;
+	}
+
+	sysrq_ch = port->sysrq_ch;
+	port->sysrq_ch = 0;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	if (sysrq_ch)
+		handle_sysrq(sysrq_ch);
+}
 #else	/* CONFIG_MAGIC_SYSRQ_SERIAL */
 static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
 {
@@ -531,6 +550,11 @@ static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
 {
 	spin_unlock(&port->lock);
 }
+static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
+		unsigned long flags)
+{
+	spin_unlock_irqrestore(&port->lock, flags);
+}
 #endif	/* CONFIG_MAGIC_SYSRQ_SERIAL */
 
 /*