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-rw-r--r--drivers/tty/hvc/hvc_xen.c30
-rw-r--r--drivers/tty/n_hdlc.c23
-rw-r--r--drivers/tty/serdev/core.c14
-rw-r--r--drivers/tty/serial/8250/8250_fintek.c20
4 files changed, 63 insertions, 24 deletions
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 71e0dd2c0ce5..ebaf7500f48f 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -37,6 +37,8 @@ struct xencons_info {
struct xenbus_device *xbdev;
struct xencons_interface *intf;
unsigned int evtchn;
+ XENCONS_RING_IDX out_cons;
+ unsigned int out_cons_same;
struct hvc_struct *hvc;
int irq;
int vtermno;
@@ -138,6 +140,8 @@ static int domU_read_console(uint32_t vtermno, char *buf, int len)
XENCONS_RING_IDX cons, prod;
int recv = 0;
struct xencons_info *xencons = vtermno_to_xencons(vtermno);
+ unsigned int eoiflag = 0;
+
if (xencons == NULL)
return -EINVAL;
intf = xencons->intf;
@@ -157,7 +161,27 @@ static int domU_read_console(uint32_t vtermno, char *buf, int len)
mb(); /* read ring before consuming */
intf->in_cons = cons;
- notify_daemon(xencons);
+ /*
+ * When to mark interrupt having been spurious:
+ * - there was no new data to be read, and
+ * - the backend did not consume some output bytes, and
+ * - the previous round with no read data didn't see consumed bytes
+ * (we might have a race with an interrupt being in flight while
+ * updating xencons->out_cons, so account for that by allowing one
+ * round without any visible reason)
+ */
+ if (intf->out_cons != xencons->out_cons) {
+ xencons->out_cons = intf->out_cons;
+ xencons->out_cons_same = 0;
+ }
+ if (recv) {
+ notify_daemon(xencons);
+ } else if (xencons->out_cons_same++ > 1) {
+ eoiflag = XEN_EOI_FLAG_SPURIOUS;
+ }
+
+ xen_irq_lateeoi(xencons->irq, eoiflag);
+
return recv;
}
@@ -386,7 +410,7 @@ static int xencons_connect_backend(struct xenbus_device *dev,
if (ret)
return ret;
info->evtchn = evtchn;
- irq = bind_evtchn_to_irq(evtchn);
+ irq = bind_interdomain_evtchn_to_irq_lateeoi(dev, evtchn);
if (irq < 0)
return irq;
info->irq = irq;
@@ -551,7 +575,7 @@ static int __init xen_hvc_init(void)
return r;
info = vtermno_to_xencons(HVC_COOKIE);
- info->irq = bind_evtchn_to_irq(info->evtchn);
+ info->irq = bind_evtchn_to_irq_lateeoi(info->evtchn);
}
if (info->irq < 0)
info->irq = 0; /* NO_IRQ */
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 7e0884ecc74f..23ba1fc99df8 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -140,6 +140,8 @@ struct n_hdlc {
struct n_hdlc_buf_list rx_buf_list;
struct n_hdlc_buf_list tx_free_buf_list;
struct n_hdlc_buf_list rx_free_buf_list;
+ struct work_struct write_work;
+ struct tty_struct *tty_for_write_work;
};
/*
@@ -154,6 +156,7 @@ static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *list);
/* Local functions */
static struct n_hdlc *n_hdlc_alloc(void);
+static void n_hdlc_tty_write_work(struct work_struct *work);
/* max frame size for memory allocations */
static int maxframe = 4096;
@@ -210,6 +213,8 @@ static void n_hdlc_tty_close(struct tty_struct *tty)
wake_up_interruptible(&tty->read_wait);
wake_up_interruptible(&tty->write_wait);
+ cancel_work_sync(&n_hdlc->write_work);
+
n_hdlc_free_buf_list(&n_hdlc->rx_free_buf_list);
n_hdlc_free_buf_list(&n_hdlc->tx_free_buf_list);
n_hdlc_free_buf_list(&n_hdlc->rx_buf_list);
@@ -241,6 +246,8 @@ static int n_hdlc_tty_open(struct tty_struct *tty)
return -ENFILE;
}
+ INIT_WORK(&n_hdlc->write_work, n_hdlc_tty_write_work);
+ n_hdlc->tty_for_write_work = tty;
tty->disc_data = n_hdlc;
tty->receive_room = 65536;
@@ -335,6 +342,20 @@ check_again:
} /* end of n_hdlc_send_frames() */
/**
+ * n_hdlc_tty_write_work - Asynchronous callback for transmit wakeup
+ * @work: pointer to work_struct
+ *
+ * Called when low level device driver can accept more send data.
+ */
+static void n_hdlc_tty_write_work(struct work_struct *work)
+{
+ struct n_hdlc *n_hdlc = container_of(work, struct n_hdlc, write_work);
+ struct tty_struct *tty = n_hdlc->tty_for_write_work;
+
+ n_hdlc_send_frames(n_hdlc, tty);
+} /* end of n_hdlc_tty_write_work() */
+
+/**
* n_hdlc_tty_wakeup - Callback for transmit wakeup
* @tty: pointer to associated tty instance data
*
@@ -344,7 +365,7 @@ static void n_hdlc_tty_wakeup(struct tty_struct *tty)
{
struct n_hdlc *n_hdlc = tty->disc_data;
- n_hdlc_send_frames(n_hdlc, tty);
+ schedule_work(&n_hdlc->write_work);
} /* end of n_hdlc_tty_wakeup() */
/**
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index f1324fe99378..92e3433276f8 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -727,10 +727,24 @@ static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
{
acpi_status status;
+ bool skip;
+ int ret;
if (!has_acpi_companion(ctrl->dev.parent))
return -ENODEV;
+ /*
+ * Skip registration on boards where the ACPI tables are known to
+ * contain buggy devices. Note serdev_controller_add() must still
+ * succeed in this case, so that the proper serdev devices can be
+ * added "manually" later.
+ */
+ ret = acpi_quirk_skip_serdev_enumeration(ctrl->dev.parent, &skip);
+ if (ret)
+ return ret;
+ if (skip)
+ return 0;
+
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
SERDEV_ACPI_MAX_SCAN_DEPTH,
acpi_serdev_add_device, NULL, ctrl, NULL);
diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
index 31c9e83ea3cb..251f0018ae8c 100644
--- a/drivers/tty/serial/8250/8250_fintek.c
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -290,25 +290,6 @@ static void fintek_8250_set_max_fifo(struct fintek_8250 *pdata)
}
}
-static void fintek_8250_goto_highspeed(struct uart_8250_port *uart,
- struct fintek_8250 *pdata)
-{
- sio_write_reg(pdata, LDN, pdata->index);
-
- switch (pdata->pid) {
- case CHIP_ID_F81966:
- case CHIP_ID_F81866: /* set uart clock for high speed serial mode */
- sio_write_mask_reg(pdata, F81866_UART_CLK,
- F81866_UART_CLK_MASK,
- F81866_UART_CLK_14_769MHZ);
-
- uart->port.uartclk = 921600 * 16;
- break;
- default: /* leave clock speed untouched */
- break;
- }
-}
-
static void fintek_8250_set_termios(struct uart_port *port,
struct ktermios *termios,
struct ktermios *old)
@@ -430,7 +411,6 @@ static int probe_setup_port(struct fintek_8250 *pdata,
fintek_8250_set_irq_mode(pdata, level_mode);
fintek_8250_set_max_fifo(pdata);
- fintek_8250_goto_highspeed(uart, pdata);
fintek_8250_exit_key(addr[i]);