Merge tag 'tty-5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are a number of small tty core and serial driver fixes for
  5.0-rc4 to resolve some reported issues.

  Nothing major, the small serial driver fixes, a tty core fixup for a
  crash that was reported, and some good vt fixes from Nicolas Pitre as
  he seems to be auditing that chunk of code a lot lately.

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

* tag 'tty-5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: fsl_lpuart: fix maximum acceptable baud rate with over-sampling
  tty: serial: qcom_geni_serial: Allow mctrl when flow control is disabled
  tty: Handle problem if line discipline does not have receive_buf
  vgacon: unconfuse vc_origin when using soft scrollback
  vt: invoke notifier on screen size change
  vt: always call notifier with the console lock held
  vt: make vt_console_print() compatible with the unicode screen buffer
  tty/n_hdlc: fix __might_sleep warning
  serial: 8250: Fix serial8250 initialization crash
  uart: Fix crash in uart_write and uart_put_char

8 files changed, 44 insertions, 52 deletions

diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 4164414d4c64..8bdf42bc8fc8 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -597,6 +597,7 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
                                 /* too large for caller's buffer */
                                 ret = -EOVERFLOW;
                         } else {
+                                __set_current_state(TASK_RUNNING);
                                 if (copy_to_user(buf, rbuf->buf, rbuf->count))
                                         ret = -EFAULT;
                                 else
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 189ab1212d9a..e441221e04b9 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1070,15 +1070,16 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 
                         ret = 0;
                 }
-        }
 
-        /* Initialise interrupt backoff work if required */
-        if (up->overrun_backoff_time_ms > 0) {
-                uart->overrun_backoff_time_ms = up->overrun_backoff_time_ms;
-                INIT_DELAYED_WORK(&uart->overrun_backoff,
-                                  serial_8250_overrun_backoff_work);
-        } else {
-                uart->overrun_backoff_time_ms = 0;
+                /* Initialise interrupt backoff work if required */
+                if (up->overrun_backoff_time_ms > 0) {
+                        uart->overrun_backoff_time_ms =
+                                up->overrun_backoff_time_ms;
+                        INIT_DELAYED_WORK(&uart->overrun_backoff,
+                                        serial_8250_overrun_backoff_work);
+                } else {
+                        uart->overrun_backoff_time_ms = 0;
+                }
         }
 
         mutex_unlock(&serial_mutex);
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 241a48e5052c..debdd1b9e01a 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1697,7 +1697,7 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
         }
 
         /* ask the core to calculate the divisor */
-        baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
+        baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 4);
 
         spin_lock_irqsave(&sport->port.lock, flags);
 
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index a72d6d9fb983..38016609c7fa 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -225,7 +225,7 @@ static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
         unsigned int mctrl = TIOCM_DSR | TIOCM_CAR;
         u32 geni_ios;
 
-        if (uart_console(uport) || !uart_cts_enabled(uport)) {
+        if (uart_console(uport)) {
                 mctrl |= TIOCM_CTS;
         } else {
                 geni_ios = readl_relaxed(uport->membase + SE_GENI_IOS);
@@ -241,7 +241,7 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
 {
         u32 uart_manual_rfr = 0;
 
-        if (uart_console(uport) || !uart_cts_enabled(uport))
+        if (uart_console(uport))
                 return;
 
         if (!(mctrl & TIOCM_RTS))
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index d4cca5bdaf1c..5c01bb6d1c24 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -550,10 +550,12 @@ static int uart_put_char(struct tty_struct *tty, unsigned char c)
         int ret = 0;
 
         circ = &state->xmit;
-        if (!circ->buf)
+        port = uart_port_lock(state, flags);
+        if (!circ->buf) {
+                uart_port_unlock(port, flags);
                 return 0;
+        }
 
-        port = uart_port_lock(state, flags);
         if (port && uart_circ_chars_free(circ) != 0) {
                 circ->buf[circ->head] = c;
                 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
@@ -586,11 +588,13 @@ static int uart_write(struct tty_struct *tty,
                 return -EL3HLT;
         }
 
+        port = uart_port_lock(state, flags);
         circ = &state->xmit;
-        if (!circ->buf)
+        if (!circ->buf) {
+                uart_port_unlock(port, flags);
                 return 0;
+        }
 
-        port = uart_port_lock(state, flags);
         while (port) {
                 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
                 if (count < c)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 23c6fd238422..21ffcce16927 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2189,7 +2189,8 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
         ld = tty_ldisc_ref_wait(tty);
         if (!ld)
                 return -EIO;
-        ld->ops->receive_buf(tty, &ch, &mbz, 1);
+        if (ld->ops->receive_buf)
+                ld->ops->receive_buf(tty, &ch, &mbz, 1);
         tty_ldisc_deref(ld);
         return 0;
 }
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 41ec8e5010f3..bba75560d11e 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -1272,6 +1272,7 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
         if (con_is_visible(vc))
                 update_screen(vc);
         vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
+        notify_update(vc);
         return err;
 }
 
@@ -2764,8 +2765,8 @@ rescan_last_byte:
         con_flush(vc, draw_from, draw_to, &draw_x);
         vc_uniscr_debug_check(vc);
         console_conditional_schedule();
-        console_unlock();
         notify_update(vc);
+        console_unlock();
         return n;
 }
 
@@ -2884,8 +2885,7 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
         unsigned char c;
         static DEFINE_SPINLOCK(printing_lock);
         const ushort *start;
-        ushort cnt = 0;
-        ushort myx;
+        ushort start_x, cnt;
         int kmsg_console;
 
         /* console busy or not yet initialized */
@@ -2898,10 +2898,6 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
         if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
                 vc = vc_cons[kmsg_console - 1].d;
 
-        /* read `x' only after setting currcons properly (otherwise
-           the `x' macro will read the x of the foreground console). */
-        myx = vc->vc_x;
-
         if (!vc_cons_allocated(fg_console)) {
                 /* impossible */
                 /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
@@ -2916,53 +2912,41 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
                 hide_cursor(vc);
 
         start = (ushort *)vc->vc_pos;
-
-        /* Contrived structure to try to emulate original need_wrap behaviour
-         * Problems caused when we have need_wrap set on '\n' character */
+        start_x = vc->vc_x;
+        cnt = 0;
         while (count--) {
                 c = *b++;
                 if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
-                        if (cnt > 0) {
-                                if (con_is_visible(vc))
-                                        vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
-                                vc->vc_x += cnt;
-                                if (vc->vc_need_wrap)
-                                        vc->vc_x--;
-                                cnt = 0;
-                        }
+                        if (cnt && con_is_visible(vc))
+                                vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x);
+                        cnt = 0;
                         if (c == 8) {           /* backspace */
                                 bs(vc);
                                 start = (ushort *)vc->vc_pos;
-                                myx = vc->vc_x;
+                                start_x = vc->vc_x;
                                 continue;
                         }
                         if (c != 13)
                                 lf(vc);
                         cr(vc);
                         start = (ushort *)vc->vc_pos;
-                        myx = vc->vc_x;
+                        start_x = vc->vc_x;
                         if (c == 10 || c == 13)
                                 continue;
                 }
+                vc_uniscr_putc(vc, c);
                 scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
                 notify_write(vc, c);
                 cnt++;
-                if (myx == vc->vc_cols - 1) {
-                        vc->vc_need_wrap = 1;
-                        continue;
-                }
-                vc->vc_pos += 2;
-                myx++;
-        }
-        if (cnt > 0) {
-                if (con_is_visible(vc))
-                        vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
-                vc->vc_x += cnt;
-                if (vc->vc_x == vc->vc_cols) {
-                        vc->vc_x--;
+                if (vc->vc_x == vc->vc_cols - 1) {
                         vc->vc_need_wrap = 1;
+                } else {
+                        vc->vc_pos += 2;
+                        vc->vc_x++;
                 }
         }
+        if (cnt && con_is_visible(vc))
+                vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x);
         set_cursor(vc);
         notify_update(vc);
 
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 09731b2f6815..c6b3bdbbdbc9 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -271,6 +271,7 @@ static void vgacon_scrollback_update(struct vc_data *c, int t, int count)
 
 static void vgacon_restore_screen(struct vc_data *c)
 {
+        c->vc_origin = c->vc_visible_origin;
         vgacon_scrollback_cur->save = 0;
 
         if (!vga_is_gfx && !vgacon_scrollback_cur->restore) {
@@ -287,8 +288,7 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)
         int start, end, count, soff;
 
         if (!lines) {
-                c->vc_visible_origin = c->vc_origin;
-                vga_set_mem_top(c);
+                vgacon_restore_screen(c);
                 return;
         }
 
@@ -298,6 +298,7 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)
         if (!vgacon_scrollback_cur->save) {
                 vgacon_cursor(c, CM_ERASE);
                 vgacon_save_screen(c);
+                c->vc_origin = (unsigned long)c->vc_screenbuf;
                 vgacon_scrollback_cur->save = 1;
         }
 
@@ -335,7 +336,7 @@ static void vgacon_scrolldelta(struct vc_data *c, int lines)
                 int copysize;
 
                 int diff = c->vc_rows - count;
-                void *d = (void *) c->vc_origin;
+                void *d = (void *) c->vc_visible_origin;
                 void *s = (void *) c->vc_screenbuf;
 
                 count *= c->vc_size_row;