Merge tag 'tty-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull TTY/serial patches from Greg KH:
 "tty and serial merge for 3.4-rc1

  Here's the big serial and tty merge for the 3.4-rc1 tree.

  There's loads of fixes and reworks in here from Jiri for the tty
  layer, and a number of patches from Alan to help try to wrestle the vt
  layer into a sane model.

  Other than that, lots of driver updates and fixes, and other minor
  stuff, all detailed in the shortlog."

* tag 'tty-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (132 commits)
  serial: pxa: add clk_prepare/clk_unprepare calls
  TTY: Wrong unicode value copied in con_set_unimap()
  serial: PL011: clear pending interrupts
  serial: bfin-uart: Don't access tty circular buffer in TX DMA interrupt after it is reset.
  vt: NULL dereference in vt_do_kdsk_ioctl()
  tty: serial: vt8500: fix annotations for probe/remove
  serial: remove back and forth conversions in serial_out_sync
  serial: use serial_port_in/out vs serial_in/out in 8250
  serial: introduce generic port in/out helpers
  serial: reduce number of indirections in 8250 code
  serial: delete useless void casts in 8250.c
  serial: make 8250's serial_in shareable to other drivers.
  serial: delete last unused traces of pausing I/O in 8250
  pch_uart: Add module parameter descriptions
  pch_uart: Use existing default_baud in setup_console
  pch_uart: Add user_uartclk parameter
  pch_uart: Add Fish River Island II uart clock quirks
  pch_uart: Use uartclk instead of base_baud
  mpc5200b/uart: select more tolerant uart prescaler on low baudrates
  tty: moxa: fix bit test in moxa_start()
  ...

1 files changed, 43 insertions, 8 deletions

diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index a0f3d6c4d39d..8308fc7cdc26 100644
--- a/drivers/tty/vt/consolemap.c
+++ b/drivers/tty/vt/consolemap.c
@@ -516,6 +516,7 @@ int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
 	int err = 0, err1, i;
 	struct uni_pagedir *p, *q;
 
+	/* Save original vc_unipagdir_loc in case we allocate a new one */
 	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
 	if (p->readonly) return -EIO;
 	
@@ -528,26 +529,57 @@ int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
 		err1 = con_clear_unimap(vc, NULL);
 		if (err1) return err1;
 		
+		/*
+		 * Since refcount was > 1, con_clear_unimap() allocated a
+		 * a new uni_pagedir for this vc.  Re: p != q
+		 */
 		q = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
-		for (i = 0, l = 0; i < 32; i++)
+
+		/*
+		 * uni_pgdir is a 32*32*64 table with rows allocated
+		 * when its first entry is added.  The unicode value must
+		 * still be incremented for empty rows.  We are copying
+		 * entries from "p" (old) to "q" (new).
+		 */
+		l = 0;		/* unicode value */
+		for (i = 0; i < 32; i++)
 		if ((p1 = p->uni_pgdir[i]))
 			for (j = 0; j < 32; j++)
-			if ((p2 = p1[j]))
+			if ((p2 = p1[j])) {
 				for (k = 0; k < 64; k++, l++)
 				if (p2[k] != 0xffff) {
+					/*
+					 * Found one, copy entry for unicode
+					 * l with fontpos value p2[k].
+					 */
 					err1 = con_insert_unipair(q, l, p2[k]);
 					if (err1) {
 						p->refcount++;
 						*vc->vc_uni_pagedir_loc = (unsigned long)p;
 						con_release_unimap(q);
 						kfree(q);
-						return err1; 
+						return err1;
 					}
-              			}
-              	p = q;
-	} else if (p == dflt)
+				}
+			} else {
+				/* Account for row of 64 empty entries */
+				l += 64;
+			}
+		else
+			/* Account for empty table */
+			l += 32 * 64;
+
+		/*
+		 * Finished copying font table, set vc_uni_pagedir to new table
+		 */
+		p = q;
+	} else if (p == dflt) {
 		dflt = NULL;
-	
+	}
+
+	/*
+	 * Insert user specified unicode pairs into new table.
+	 */
 	while (ct--) {
 		unsigned short unicode, fontpos;
 		__get_user(unicode, &list->unicode);
@@ -557,11 +589,14 @@ int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
 		list++;
 	}
 	
+	/*
+	 * Merge with fontmaps of any other virtual consoles.
+	 */
 	if (con_unify_unimap(vc, p))
 		return err;
 
 	for (i = 0; i <= 3; i++)
-		set_inverse_transl(vc, p, i); /* Update all inverse translations */
+		set_inverse_transl(vc, p, i); /* Update inverse translations */
 	set_inverse_trans_unicode(vc, p);
   
 	return err;