Merge tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial updates from Greg KH:
 "Here is the big set of tty/serial driver changes for 6.10-rc1.
  Included in here are:

   - Usual good set of api cleanups and evolution by Jiri Slaby to make
     the serial interfaces move out of the 1990's by using kfifos
     instead of hand-rolling their own logic.

   - 8250_exar driver updates

   - max3100 driver updates

   - sc16is7xx driver updates

   - exar driver updates

   - sh-sci driver updates

   - tty ldisc api addition to help refuse bindings

   - other smaller serial driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (113 commits)
  serial: Clear UPF_DEAD before calling tty_port_register_device_attr_serdev()
  serial: imx: Raise TX trigger level to 8
  serial: 8250_pnp: Simplify "line" related code
  serial: sh-sci: simplify locking when re-issuing RXDMA fails
  serial: sh-sci: let timeout timer only run when DMA is scheduled
  serial: sh-sci: describe locking requirements for invalidating RXDMA
  serial: sh-sci: protect invalidating RXDMA on shutdown
  tty: add the option to have a tty reject a new ldisc
  serial: core: Call device_set_awake_path() for console port
  dt-bindings: serial: brcm,bcm2835-aux-uart: convert to dtschema
  tty: serial: uartps: Add support for uartps controller reset
  arm64: zynqmp: Add resets property for UART nodes
  dt-bindings: serial: cdns,uart: Add optional reset property
  serial: 8250_pnp: Switch to DEFINE_SIMPLE_DEV_PM_OPS()
  serial: 8250_exar: Keep the includes sorted
  serial: 8250_exar: Make type of bit the same in exar_ee_*_bit()
  serial: 8250_exar: Use BIT() in exar_ee_read()
  serial: 8250_exar: Switch to use dev_err_probe()
  serial: 8250_exar: Return directly from switch-cases
  serial: 8250_exar: Decrease indentation level
  ...

Author: torvalds

Documentation/admin-guide/kernel-parameters.txt

@@ -788,6 +788,25 @@
 			Documentation/networking/netconsole.rst for an
 			alternative.
 
+		<DEVNAME>:<n>.<n>[,options]
+			Use the specified serial port on the serial core bus.
+			The addressing uses DEVNAME of the physical serial port
+			device, followed by the serial core controller instance,
+			and the serial port instance. The options are the same
+			as documented for the ttyS addressing above.
+
+			The mapping of the serial ports to the tty instances
+			can be viewed with:
+
+			$ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
+			/sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
+
+			In the above example, the console can be addressed with
+			console=00:04:0.0. Note that a console addressed this
+			way will only get added when the related device driver
+			is ready. The use of an earlycon parameter in addition to
+			the console may be desired for console output early on.
+
 		uart[8250],io,<addr>[,options]
 		uart[8250],mmio,<addr>[,options]
 		uart[8250],mmio16,<addr>[,options]

Documentation/admin-guide/sysrq.rst

@@ -161,6 +161,8 @@ Command	    Function
             will be printed to your console. (``0``, for example would make
             it so that only emergency messages like PANICs or OOPSes would
             make it to your console.)
+
+``R``	    Replay the kernel log messages on consoles.
 =========== ===================================================================
 
 Okay, so what can I use them for?
@@ -211,6 +213,13 @@ processes.
 "just thaw ``it(j)``" is useful if your system becomes unresponsive due to a
 frozen (probably root) filesystem via the FIFREEZE ioctl.
 
+``Replay logs(R)`` is useful to view the kernel log messages when system is hung
+or you are not able to use dmesg command to view the messages in printk buffer.
+User may have to press the key combination multiple times if console system is
+busy. If it is completely locked up, then messages won't be printed. Output
+messages depend on current console loglevel, which can be modified using
+sysrq[0-9] (see above).
+
 Sometimes SysRq seems to get 'stuck' after using it, what can I do?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

Documentation/devicetree/bindings/serial/actions,owl-uart.txt

@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/actions,owl-uart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Actions Semi Owl UART
+
+maintainers:
+  - Kanak Shilledar <[email protected]>
+
+allOf:
+  - $ref: serial.yaml
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - actions,s500-uart
+          - actions,s900-uart
+      - const: actions,owl-uart
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/actions,s500-cmu.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    uart0: serial@b0126000 {
+        compatible = "actions,s500-uart", "actions,owl-uart";
+        reg = <0xb0126000 0x1000>;
+        clocks = <&cmu CLK_UART0>;
+        interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
+    };

Documentation/devicetree/bindings/serial/actions,owl-uart.yaml

@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/brcm,bcm2835-aux-uart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: BCM2835 AUXILIARY UART
+
+maintainers:
+  - Pratik Farkase <[email protected]>
+  - Florian Fainelli <[email protected]>
+  - Stefan Wahren <[email protected]>
+
+allOf:
+  - $ref: serial.yaml
+
+properties:
+  compatible:
+    const: brcm,bcm2835-aux-uart
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/bcm2835-aux.h>
+    serial@7e215040 {
+        compatible = "brcm,bcm2835-aux-uart";
+        reg = <0x7e215040 0x40>;
+        interrupts = <1 29>;
+        clocks = <&aux BCM2835_AUX_CLOCK_UART>;
+    };

Documentation/devicetree/bindings/serial/brcm,bcm2835-aux-uart.txt

@@ -46,6 +46,9 @@ properties:
   power-domains:
     maxItems: 1
 
+  resets:
+    maxItems: 1
+
 required:
   - compatible
   - reg

Documentation/devicetree/bindings/serial/brcm,bcm2835-aux-uart.yaml

@@ -68,6 +68,7 @@ properties:
               - renesas,scif-r8a779a0     # R-Car V3U
               - renesas,scif-r8a779f0     # R-Car S4-8
               - renesas,scif-r8a779g0     # R-Car V4H
+              - renesas,scif-r8a779h0     # R-Car V4M
           - const: renesas,rcar-gen4-scif # R-Car Gen4
           - const: renesas,scif           # generic SCIF compatible UART
 

Documentation/devicetree/bindings/serial/cdns,uart.yaml

@@ -906,6 +906,7 @@
 			reg = <0x0 0xff000000 0x0 0x1000>;
 			clock-names = "uart_clk", "pclk";
 			power-domains = <&zynqmp_firmware PD_UART_0>;
+			resets = <&zynqmp_reset ZYNQMP_RESET_UART0>;
 		};
 
 		uart1: serial@ff010000 {
@@ -917,6 +918,7 @@
 			reg = <0x0 0xff010000 0x0 0x1000>;
 			clock-names = "uart_clk", "pclk";
 			power-domains = <&zynqmp_firmware PD_UART_1>;
+			resets = <&zynqmp_reset ZYNQMP_RESET_UART1>;
 		};
 
 		usb0: usb@ff9d0000 {

Documentation/devicetree/bindings/serial/renesas,scif.yaml

@@ -1578,7 +1578,13 @@ static void __exit amiga_serial_remove(struct platform_device *pdev)
 	free_irq(IRQ_AMIGA_RBF, state);
 }
 
-static struct platform_driver amiga_serial_driver = {
+/*
+ * amiga_serial_remove() lives in .exit.text. For drivers registered via
+ * module_platform_driver_probe() this is ok because they cannot get unbound at
+ * runtime. So mark the driver struct with __refdata to prevent modpost
+ * triggering a section mismatch warning.
+ */
+static struct platform_driver amiga_serial_driver __refdata = {
 	.remove_new = __exit_p(amiga_serial_remove),
 	.driver   = {
 		.name	= "amiga-serial",

arch/arm64/boot/dts/xilinx/zynqmp.dtsi

@@ -558,7 +558,7 @@ static void xencons_backend_changed(struct xenbus_device *dev,
 			break;
 		fallthrough;	/* Missed the backend's CLOSING state */
 	case XenbusStateClosing: {
-		struct xencons_info *info = dev_get_drvdata(&dev->dev);;
+		struct xencons_info *info = dev_get_drvdata(&dev->dev);
 
 		/*
 		 * Don't tear down the evtchn and grant ref before the other

drivers/tty/amiserial.c

@@ -4010,7 +4010,7 @@ static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc)
 	mux_net = netdev_priv(net);
 	mux_net->dlci = dlci;
 	kref_init(&mux_net->ref);
-	strncpy(nc->if_name, net->name, IFNAMSIZ); /* return net name */
+	strscpy(nc->if_name, net->name); /* return net name */
 
 	/* reconfigure dlci for network */
 	dlci->prev_adaption = dlci->adaption;

drivers/tty/hvc/hvc_xen.c

@@ -413,20 +413,18 @@ static int stop_tx_dma(struct uart_8250_port *p)
 static int brcmuart_tx_dma(struct uart_8250_port *p)
 {
 	struct brcmuart_priv *priv = p->port.private_data;
-	struct circ_buf *xmit = &p->port.state->xmit;
+	struct tty_port *tport = &p->port.state->port;
 	u32 tx_size;
 
 	if (uart_tx_stopped(&p->port) || priv->tx_running ||
-		uart_circ_empty(xmit)) {
+		kfifo_is_empty(&tport->xmit_fifo)) {
 		return 0;
 	}
-	tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
 
 	priv->dma.tx_err = 0;
-	memcpy(priv->tx_buf, &xmit->buf[xmit->tail], tx_size);
-	uart_xmit_advance(&p->port, tx_size);
+	tx_size = uart_fifo_out(&p->port, priv->tx_buf, UART_XMIT_SIZE);
 
-	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
 		uart_write_wakeup(&p->port);
 
 	udma_writel(priv, REGS_DMA_TX, UDMA_TX_TRANSFER_LEN, tx_size);
@@ -540,15 +538,15 @@ static void brcmuart_tx_isr(struct uart_port *up, u32 isr)
 	struct brcmuart_priv *priv = up->private_data;
 	struct device *dev = up->dev;
 	struct uart_8250_port *port_8250 = up_to_u8250p(up);
-	struct circ_buf	*xmit = &port_8250->port.state->xmit;
+	struct tty_port *tport = &port_8250->port.state->port;
 
 	if (isr & UDMA_INTR_TX_ABORT) {
 		if (priv->tx_running)
 			dev_err(dev, "Unexpected TX_ABORT interrupt\n");
 		return;
 	}
 	priv->tx_running = false;
-	if (!uart_circ_empty(xmit) && !uart_tx_stopped(up))
+	if (!kfifo_is_empty(&tport->xmit_fifo) && !uart_tx_stopped(up))
 		brcmuart_tx_dma(port_8250);
 }
 

drivers/tty/n_gsm.c

@@ -15,6 +15,7 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/cleanup.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/ioport.h>
@@ -41,6 +42,8 @@
 
 #include <asm/irq.h>
 
+#include "../serial_base.h"	/* For serial_base_add_isa_preferred_console() */
+
 #include "8250.h"
 
 /*
@@ -280,7 +283,8 @@ static void serial8250_backup_timeout(struct timer_list *t)
 	 */
 	lsr = serial_lsr_in(up);
 	if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
-	    (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
+	    (!kfifo_is_empty(&up->port.state->port.xmit_fifo) ||
+	     up->port.x_char) &&
 	    (lsr & UART_LSR_THRE)) {
 		iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
 		iir |= UART_IIR_THRI;
@@ -559,6 +563,8 @@ static void __init serial8250_isa_init_ports(void)
 		port->irqflags |= irqflag;
 		if (serial8250_isa_config != NULL)
 			serial8250_isa_config(i, &up->port, &up->capabilities);
+
+		serial_base_add_isa_preferred_console(serial8250_reg.dev_name, i);
 	}
 }