TTY/Serial driver fixes for 6.12-rc4

Here are some small tty and serial driver fixes for 6.12-rc4.  Included
 in here are:
   - qcom-geni serial driver fixes, wow what a mess of a UART chip that
     thing is...
   - vt infoleak fix for odd font sizes
   - imx serial driver bugfix
   - yet-another n_gsm ldisc bugfix, slowly chipping down the issues in
     that piece of code.
 
 All of these have been in linux-next for over a week with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 
 iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZxUGDQ8cZ3JlZ0Brcm9h
 aC5jb20ACgkQMUfUDdst+ymS+ACfQaKXHHy0WZ/kB22Eif7KgKsx+D0AnjxH+H5l
 knORLhrVW+V41wyk9QM/
 =qbdY
 -----END PGP SIGNATURE-----

Merge tag 'tty-6.12-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 for 6.12-rc4:

   - qcom-geni serial driver fixes, wow what a mess of a UART chip that
     thing is...

   - vt infoleak fix for odd font sizes

   - imx serial driver bugfix

   - yet-another n_gsm ldisc bugfix, slowly chipping down the issues in
     that piece of code

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

* tag 'tty-6.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: qcom-geni: rename suspend functions
  serial: qcom-geni: drop unused receive parameter
  serial: qcom-geni: drop flip buffer WARN()
  serial: qcom-geni: fix rx cancel dma status bit
  serial: qcom-geni: fix receiver enable
  serial: qcom-geni: fix dma rx cancellation
  serial: qcom-geni: fix shutdown race
  serial: qcom-geni: revert broken hibernation support
  serial: qcom-geni: fix polled console initialisation
  serial: imx: Update mctrl old_status on RTSD interrupt
  tty: n_gsm: Fix use-after-free in gsm_cleanup_mux
  vt: prevent kernel-infoleak in con_font_get()

drivers/tty/n_gsm.c

@@ -3157,6 +3157,8 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc)
 	mutex_unlock(&gsm->mutex);
 	/* Now wipe the queues */
 	tty_ldisc_flush(gsm->tty);
+
+	guard(spinlock_irqsave)(&gsm->tx_lock);
 	list_for_each_entry_safe(txq, ntxq, &gsm->tx_ctrl_list, list)
 		kfree(txq);
 	INIT_LIST_HEAD(&gsm->tx_ctrl_list);

drivers/tty/serial/imx.c

@@ -762,6 +762,21 @@ static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id)
 
 	imx_uart_writel(sport, USR1_RTSD, USR1);
 	usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
+	/*
+	 * Update sport->old_status here, so any follow-up calls to
+	 * imx_uart_mctrl_check() will be able to recognize that RTS
+	 * state changed since last imx_uart_mctrl_check() call.
+	 *
+	 * In case RTS has been detected as asserted here and later on
+	 * deasserted by the time imx_uart_mctrl_check() was called,
+	 * imx_uart_mctrl_check() can detect the RTS state change and
+	 * trigger uart_handle_cts_change() to unblock the port for
+	 * further TX transfers.
+	 */
+	if (usr1 & USR1_RTSS)
+		sport->old_status |= TIOCM_CTS;
+	else
+		sport->old_status &= ~TIOCM_CTS;
 	uart_handle_cts_change(&sport->port, usr1);
 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
 

drivers/tty/serial/qcom_geni_serial.c

@@ -147,6 +147,7 @@ static struct uart_driver qcom_geni_uart_driver;
 
 static void __qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport);
 static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport);
+static int qcom_geni_serial_port_setup(struct uart_port *uport);
 
 static inline struct qcom_geni_serial_port *to_dev_port(struct uart_port *uport)
 {
@@ -395,6 +396,23 @@ static void qcom_geni_serial_poll_put_char(struct uart_port *uport,
 	writel(c, uport->membase + SE_GENI_TX_FIFOn);
 	qcom_geni_serial_poll_tx_done(uport);
 }
+
+static int qcom_geni_serial_poll_init(struct uart_port *uport)
+{
+	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	int ret;
+
+	if (!port->setup) {
+		ret = qcom_geni_serial_port_setup(uport);
+		if (ret)
+			return ret;
+	}
+
+	if (!qcom_geni_serial_secondary_active(uport))
+		geni_se_setup_s_cmd(&port->se, UART_START_READ, 0);
+
+	return 0;
+}
 #endif
 
 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
@@ -562,7 +580,7 @@ static void handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
 }
 #endif /* CONFIG_SERIAL_QCOM_GENI_CONSOLE */
 
-static void handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop)
+static void handle_rx_uart(struct uart_port *uport, u32 bytes)
 {
 	struct qcom_geni_serial_port *port = to_dev_port(uport);
 	struct tty_port *tport = &uport->state->port;
@@ -570,9 +588,8 @@ static void handle_rx_uart(struct uart_port *uport, u32 bytes, bool drop)
 
 	ret = tty_insert_flip_string(tport, port->rx_buf, bytes);
 	if (ret != bytes) {
-		dev_err(uport->dev, "%s:Unable to push data ret %d_bytes %d\n",
+		dev_err_ratelimited(uport->dev, "failed to push data (%d < %u)\n",
-				__func__, ret, bytes);
+				ret, bytes);
-		WARN_ON_ONCE(1);
 	}
 	uport->icount.rx += ret;
 	tty_flip_buffer_push(tport);
@@ -787,17 +804,27 @@ static void qcom_geni_serial_start_rx_fifo(struct uart_port *uport)
 static void qcom_geni_serial_stop_rx_dma(struct uart_port *uport)
 {
 	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	bool done;
 
 	if (!qcom_geni_serial_secondary_active(uport))
 		return;
 
 	geni_se_cancel_s_cmd(&port->se);
-	qcom_geni_serial_poll_bit(uport, SE_GENI_S_IRQ_STATUS,
+	done = qcom_geni_serial_poll_bit(uport, SE_DMA_RX_IRQ_STAT,
-				  S_CMD_CANCEL_EN, true);
+			RX_EOT, true);
-
+	if (done) {
-	if (qcom_geni_serial_secondary_active(uport))
+		writel(RX_EOT | RX_DMA_DONE,
+				uport->membase + SE_DMA_RX_IRQ_CLR);
+	} else {
 		qcom_geni_serial_abort_rx(uport);
 
+		writel(1, uport->membase + SE_DMA_RX_FSM_RST);
+		qcom_geni_serial_poll_bit(uport, SE_DMA_RX_IRQ_STAT,
+				RX_RESET_DONE, true);
+		writel(RX_RESET_DONE | RX_DMA_DONE,
+				uport->membase + SE_DMA_RX_IRQ_CLR);
+	}
+
 	if (port->rx_dma_addr) {
 		geni_se_rx_dma_unprep(&port->se, port->rx_dma_addr,
 				      DMA_RX_BUF_SIZE);
@@ -846,7 +873,7 @@ static void qcom_geni_serial_handle_rx_dma(struct uart_port *uport, bool drop)
 	}
 
 	if (!drop)
-		handle_rx_uart(uport, rx_in, drop);
+		handle_rx_uart(uport, rx_in);
 
 	ret = geni_se_rx_dma_prep(&port->se, port->rx_buf,
 				  DMA_RX_BUF_SIZE,
@@ -1096,10 +1123,12 @@ static void qcom_geni_serial_shutdown(struct uart_port *uport)
 {
 	disable_irq(uport->irq);
 
+	uart_port_lock_irq(uport);
 	qcom_geni_serial_stop_tx(uport);
 	qcom_geni_serial_stop_rx(uport);
 
 	qcom_geni_serial_cancel_tx_cmd(uport);
+	uart_port_unlock_irq(uport);
 }
 
 static void qcom_geni_serial_flush_buffer(struct uart_port *uport)
@@ -1152,7 +1181,6 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport)
 			       false, true, true);
 	geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2);
 	geni_se_select_mode(&port->se, port->dev_data->mode);
-	qcom_geni_serial_start_rx(uport);
 	port->setup = true;
 
 	return 0;
@@ -1168,6 +1196,11 @@ static int qcom_geni_serial_startup(struct uart_port *uport)
 		if (ret)
 			return ret;
 	}
+
+	uart_port_lock_irq(uport);
+	qcom_geni_serial_start_rx(uport);
+	uart_port_unlock_irq(uport);
+
 	enable_irq(uport->irq);
 
 	return 0;
@@ -1253,7 +1286,6 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 	unsigned int avg_bw_core;
 	unsigned long timeout;
 
-	qcom_geni_serial_stop_rx(uport);
 	/* baud rate */
 	baud = uart_get_baud_rate(uport, termios, old, 300, 4000000);
 
@@ -1269,7 +1301,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 		dev_err(port->se.dev,
 			"Couldn't find suitable clock rate for %u\n",
 			baud * sampling_rate);
-		goto out_restart_rx;
+		return;
 	}
 
 	dev_dbg(port->se.dev, "desired_rate = %u, clk_rate = %lu, clk_div = %u\n",
@@ -1360,8 +1392,6 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 	writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
 	writel(ser_clk_cfg, uport->membase + GENI_SER_M_CLK_CFG);
 	writel(ser_clk_cfg, uport->membase + GENI_SER_S_CLK_CFG);
-out_restart_rx:
-	qcom_geni_serial_start_rx(uport);
 }
 
 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
@@ -1582,7 +1612,7 @@ static const struct uart_ops qcom_geni_console_pops = {
 #ifdef CONFIG_CONSOLE_POLL
 	.poll_get_char	= qcom_geni_serial_get_char,
 	.poll_put_char	= qcom_geni_serial_poll_put_char,
-	.poll_init = qcom_geni_serial_port_setup,
+	.poll_init = qcom_geni_serial_poll_init,
 #endif
 	.pm = qcom_geni_serial_pm,
 };
@@ -1749,7 +1779,7 @@ static void qcom_geni_serial_remove(struct platform_device *pdev)
 	uart_remove_one_port(drv, &port->uport);
 }
 
-static int qcom_geni_serial_sys_suspend(struct device *dev)
+static int qcom_geni_serial_suspend(struct device *dev)
 {
 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
 	struct uart_port *uport = &port->uport;
@@ -1766,7 +1796,7 @@ static int qcom_geni_serial_sys_suspend(struct device *dev)
 	return uart_suspend_port(private_data->drv, uport);
 }
 
-static int qcom_geni_serial_sys_resume(struct device *dev)
+static int qcom_geni_serial_resume(struct device *dev)
 {
 	int ret;
 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
@@ -1781,38 +1811,6 @@ static int qcom_geni_serial_sys_resume(struct device *dev)
 	return ret;
 }
 
-static int qcom_geni_serial_sys_hib_resume(struct device *dev)
-{
-	int ret = 0;
-	struct uart_port *uport;
-	struct qcom_geni_private_data *private_data;
-	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
-
-	uport = &port->uport;
-	private_data = uport->private_data;
-
-	if (uart_console(uport)) {
-		geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ALWAYS);
-		geni_icc_set_bw(&port->se);
-		ret = uart_resume_port(private_data->drv, uport);
-		/*
-		 * For hibernation usecase clients for
-		 * console UART won't call port setup during restore,
-		 * hence call port setup for console uart.
-		 */
-		qcom_geni_serial_port_setup(uport);
-	} else {
-		/*
-		 * Peripheral register settings are lost during hibernation.
-		 * Update setup flag such that port setup happens again
-		 * during next session. Clients of HS-UART will close and
-		 * open the port during hibernation.
-		 */
-		port->setup = false;
-	}
-	return ret;
-}
-
 static const struct qcom_geni_device_data qcom_geni_console_data = {
 	.console = true,
 	.mode = GENI_SE_FIFO,
@@ -1824,12 +1822,7 @@ static const struct qcom_geni_device_data qcom_geni_uart_data = {
 };
 
 static const struct dev_pm_ops qcom_geni_serial_pm_ops = {
-	.suspend = pm_sleep_ptr(qcom_geni_serial_sys_suspend),
+	SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_suspend, qcom_geni_serial_resume)
-	.resume = pm_sleep_ptr(qcom_geni_serial_sys_resume),
-	.freeze = pm_sleep_ptr(qcom_geni_serial_sys_suspend),
-	.poweroff = pm_sleep_ptr(qcom_geni_serial_sys_suspend),
-	.restore = pm_sleep_ptr(qcom_geni_serial_sys_hib_resume),
-	.thaw = pm_sleep_ptr(qcom_geni_serial_sys_hib_resume),
 };
 
 static const struct of_device_id qcom_geni_serial_match_table[] = {

drivers/tty/vt/vt.c

@@ -4726,7 +4726,7 @@ static int con_font_get(struct vc_data *vc, struct console_font_op *op)
 		return -EINVAL;
 
 	if (op->data) {
-		font.data = kvmalloc(max_font_size, GFP_KERNEL);
+		font.data = kvzalloc(max_font_size, GFP_KERNEL);
 		if (!font.data)
 			return -ENOMEM;
 	} else

include/linux/soc/qcom/geni-se.h

@@ -258,8 +258,8 @@ struct geni_se {
 #define RX_DMA_PARITY_ERR		BIT(5)
 #define RX_DMA_BREAK			GENMASK(8, 7)
 #define RX_GENI_GP_IRQ			GENMASK(10, 5)
-#define RX_GENI_CANCEL_IRQ		BIT(11)
 #define RX_GENI_GP_IRQ_EXT		GENMASK(13, 12)
+#define RX_GENI_CANCEL_IRQ		BIT(14)
 
 /* SE_HW_PARAM_0 fields */
 #define TX_FIFO_WIDTH_MSK		GENMASK(29, 24)