Merge tag 'char-misc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big char/misc driver update for 4.4-rc1.  Lots of
  different driver and subsystem updates, hwtracing being the largest
  with the addition of some new platforms that are now supported.  Full
  details in the shortlog.

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

* tag 'char-misc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (181 commits)
  fpga: socfpga: Fix check of return value of devm_request_irq
  lkdtm: fix ACCESS_USERSPACE test
  mcb: Destroy IDA on module unload
  mcb: Do not return zero on error path in mcb_pci_probe()
  mei: bus: set the device name before running fixup
  mei: bus: use correct lock ordering
  mei: Fix debugfs filename in error output
  char: ipmi: ipmi_ssif: Replace timeval with timespec64
  fpga: zynq-fpga: Fix issue with drvdata being overwritten.
  fpga manager: remove unnecessary null pointer checks
  fpga manager: ensure lifetime with of_fpga_mgr_get
  fpga: zynq-fpga: Change fw format to handle bin instead of bit.
  fpga: zynq-fpga: Fix unbalanced clock handling
  misc: sram: partition base address belongs to __iomem space
  coresight: etm3x: adding documentation for sysFS's cpu interface
  vme: 8-bit status/id takes 256 values, not 255
  fpga manager: Adding FPGA Manager support for Xilinx Zynq 7000
  ARM: zynq: dt: Updated devicetree for Zynq 7000 platform.
  ARM: dt: fpga: Added binding docs for Xilinx Zynq FPGA manager.
  ver_linux: proc/modules, limit text processing to 'sed'
  ...

1 files changed, 16 insertions, 2 deletions

diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index c8c6a363069c..6e3af8b42cdd 100644
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -460,6 +460,13 @@ static void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
  * - TTY layer when write's finished
  * - st_write (in context of the protocol stack)
  */
+static void work_fn_write_wakeup(struct work_struct *work)
+{
+	struct st_data_s *st_gdata = container_of(work, struct st_data_s,
+			work_write_wakeup);
+
+	st_tx_wakeup((void *)st_gdata);
+}
 void st_tx_wakeup(struct st_data_s *st_data)
 {
 	struct sk_buff *skb;
@@ -812,8 +819,12 @@ static void st_tty_wakeup(struct tty_struct *tty)
 	/* don't do an wakeup for now */
 	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 
-	/* call our internal wakeup */
-	st_tx_wakeup((void *)st_gdata);
+	/*
+	 * schedule the internal wakeup instead of calling directly to
+	 * avoid lockup (port->lock needed in tty->ops->write is
+	 * already taken here
+	 */
+	schedule_work(&st_gdata->work_write_wakeup);
 }
 
 static void st_tty_flush_buffer(struct tty_struct *tty)
@@ -881,6 +892,9 @@ int st_core_init(struct st_data_s **core_data)
 			pr_err("unable to un-register ldisc");
 		return err;
 	}
+
+	INIT_WORK(&st_gdata->work_write_wakeup, work_fn_write_wakeup);
+
 	*core_data = st_gdata;
 	return 0;
 }