Commit a8d12007 authored Nov 08, 2011 by Alan Cox Committed by Linus Torvalds Nov 08, 2011

n_gsm: Fix timings

Alek Du reported that the code erroneously applies time to jiffies
conversions twice to the t1 and t2 values. In normal use on a modem link
this cases no visible problem but on a slower link it will break as with
HZ=1000 as is typical we are running t1/t2 ten times too fast.

Alek's original patch removed the conversion from the timer setting but we
in fact have to be more careful as the contents of t1/t2 are visible via
the device API and we thus need to correct the constants.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 1ea6b8f4

drivers/tty/n_gsm.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -66,14 +66,16 @@
		static int debug;
		module_param(debug, int, 0600);

		#define T1 (HZ/10)
		#define T2 (HZ/3)
		#define N2 3
		/* Defaults: these are from the specification */

		#define T1 10 /* 100mS */
		#define T2 34 /* 333mS */
		#define N2 3 /* Retry 3 times */

		/* Use long timers for testing at low speed with debug on */
		#ifdef DEBUG_TIMING
		#define T1 HZ
		#define T2 (2 * HZ)
		#define T1 100
		#define T2 200
		#endif

		/*