[kernel] r15823 - in dists/sid/linux-2.6/debian: . patches/bugfix/sh4 patches/series

[Aurelien Jarno]

Author: aurel32
Date: Wed Jun  2 09:10:51 2010
New Revision: 15823

Log:
* [sh4] fix sh_tmu clocksource following recent nohz changes.

Added:
   dists/sid/linux-2.6/debian/patches/bugfix/sh4/
   dists/sid/linux-2.6/debian/patches/bugfix/sh4/fix-sh_tmu.patch
Modified:
   dists/sid/linux-2.6/debian/changelog
   dists/sid/linux-2.6/debian/patches/series/16

Modified: dists/sid/linux-2.6/debian/changelog
==============================================================================
--- dists/sid/linux-2.6/debian/changelog	Wed Jun  2 03:03:01 2010	(r15822)
+++ dists/sid/linux-2.6/debian/changelog	Wed Jun  2 09:10:51 2010	(r15823)
@@ -7,6 +7,9 @@
   [ Ben Hutchings ]
   * Add stable 2.6.32.15
 
+  [ Aurelien Jarno ]
+  * [sh4] fix sh_tmu clocksource following recent nohz changes.
+
  -- dann frazier <dannf at debian.org>  Tue, 01 Jun 2010 09:23:57 -0600
 
 linux-2.6 (2.6.32-15) unstable; urgency=low

Added: dists/sid/linux-2.6/debian/patches/bugfix/sh4/fix-sh_tmu.patch
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ dists/sid/linux-2.6/debian/patches/bugfix/sh4/fix-sh_tmu.patch	Wed Jun  2 09:10:51 2010	(r15823)
@@ -0,0 +1,59 @@
+From: Aurelien Jarno <aurelien at aurel32.net>
+Date: Mon, 31 May 2010 21:45:48 +0000 (+0000)
+Subject: clocksource: sh_tmu: compute mult and shift before registration
+
+clocksource: sh_tmu: compute mult and shift before registration
+
+Since commit 98962465ed9e6ea99c38e0af63fe1dcb5a79dc25 ("nohz: Prevent
+clocksource wrapping during idle"), the CPU of an R2D board never goes
+to idle. This commit assumes that mult and shift are assigned before
+the clocksource is registered. As a consequence the safe maximum sleep
+time is negative and the CPU never goes into idle.
+
+This patch fixes the problem by moving mult and shift initialization
+from sh_tmu_clocksource_enable() to sh_tmu_register_clocksource().
+
+Signed-off-by: Aurelien Jarno <aurelien at aurel32.net>
+Cc: stable at kernel.org
+Signed-off-by: Paul Mundt <lethal at linux-sh.org>
+---
+
+diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c
+index 8e44e14..de71590 100644
+--- a/drivers/clocksource/sh_tmu.c
++++ b/drivers/clocksource/sh_tmu.c
+@@ -199,16 +199,8 @@ static cycle_t sh_tmu_clocksource_read(struct clocksource *cs)
+ static int sh_tmu_clocksource_enable(struct clocksource *cs)
+ {
+ 	struct sh_tmu_priv *p = cs_to_sh_tmu(cs);
+-	int ret;
+-
+-	ret = sh_tmu_enable(p);
+-	if (ret)
+-		return ret;
+ 
+-	/* TODO: calculate good shift from rate and counter bit width */
+-	cs->shift = 10;
+-	cs->mult = clocksource_hz2mult(p->rate, cs->shift);
+-	return 0;
++	return sh_tmu_enable(p);
+ }
+ 
+ static void sh_tmu_clocksource_disable(struct clocksource *cs)
+@@ -228,6 +220,16 @@
+ 	cs->disable = sh_tmu_clocksource_disable;
+ 	cs->mask = CLOCKSOURCE_MASK(32);
+ 	cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
++
++	/* clk_get_rate() needs an enabled clock */
++	clk_enable(p->clk);
++	/* channel will be configured at parent clock / 4 */
++	p->rate = clk_get_rate(p->clk) / 4;
++	clk_disable(p->clk);
++	/* TODO: calculate good shift from rate and counter bit width */
++	cs->shift = 10;
++	cs->mult = clocksource_hz2mult(p->rate, cs->shift);
++
+ 	pr_info("sh_tmu: %s used as clock source\n", cs->name);
+ 	clocksource_register(cs);
+ 	return 0;

Modified: dists/sid/linux-2.6/debian/patches/series/16
==============================================================================
--- dists/sid/linux-2.6/debian/patches/series/16	Wed Jun  2 03:03:01 2010	(r15822)
+++ dists/sid/linux-2.6/debian/patches/series/16	Wed Jun  2 09:10:51 2010	(r15823)
@@ -1,3 +1,4 @@
 + bugfix/parisc/clear-fp-exception-flag-on-SIGFPE.patch
 - bugfix/all/revert-percpu-stable-changes-2.patch 
 + bugfix/all/stable/2.6.32.15.patch
++ bugfix/sh4/fix-sh_tmu.patch