Re: [PATCH 3.0-rc1] PM / runtime: fix broken iteration over clock ids

[Rafael J. Wysocki]

On Monday, June 06, 2011, Janusz Krzysztofik wrote:
> On Mon 06 Jun 2011 at 19:47:36 Rafael J. Wysocki wrote:
> > Hi,
> > 
> > On Sunday, June 05, 2011, Janusz Krzysztofik wrote:
> > > In its current form, pm_runtime_clk_notify() iterates through sub-
> > > strings of pm_clk_notifier_block.con_ids[0] rather than consecutive
> > > pm_clk_notifier_block.con_ids[] elements. As a noticeable result,
> > > McBSP1 port no longer worked for me on updated
> > > arch/arm/mach-omap1/pm_bus.c (commit
> > > 600b776eb39a13a28b090ba9efceb0c69d4508aa, "OMAP1 / PM: Use generic
> > > clock manipulation routines for runtime PM"), not being able to
> > > activate "fck" when required.
> > > 
> > > Tested on Amstrad Delta.
> > > 
> > > Signed-off-by: Janusz Krzysztofik <jkrzyszt@xxxxxxxxxxxx>
> > > ---
> > > 
> > >  drivers/base/power/clock_ops.c |    6 +++---
> > >  1 file changed, 3 insertions(+), 3 deletions(-)
> > > 
> > > --- git/drivers/base/power/clock_ops.c.orig	2011-05-30
> > > 22:16:35.000000000 +0200 +++
> > > git/drivers/base/power/clock_ops.c	2011-06-05 15:19:55.000000000
> > > +0200 @@ -291,7 +291,7 @@ static int pm_runtime_clk_notify(struct
> > > 
> > >  {
> > >  
> > >  	struct pm_clk_notifier_block *clknb;
> > >  	struct device *dev = data;
> > > 
> > > -	char *con_id;
> > > +	char **con_id;
> > > 
> > >  	int error;
> > >  	
> > >  	dev_dbg(dev, "%s() %ld\n", __func__, action);
> > > 
> > > @@ -309,8 +309,8 @@ static int pm_runtime_clk_notify(struct
> > > 
> > >  		dev->pwr_domain = clknb->pwr_domain;
> > >  		if (clknb->con_ids[0]) {
> > > 
> > > -			for (con_id = clknb->con_ids[0]; *con_id; con_id++)
> > > -				pm_runtime_clk_add(dev, con_id);
> > > +			for (con_id = &clknb->con_ids[0]; *con_id; con_id++)
> > > +				pm_runtime_clk_add(dev, *con_id);
> > > 
> > >  		} else {
> > >  		
> > >  			pm_runtime_clk_add(dev, NULL);
> > >  		
> > >  		}
> > 
> > First off, sorry for the breakage.  Second, while the patch is
> > correct in the part is covered, it is incomplete (it also should
> > cover the !CONFIG_PM_RUNTIME case.  So, I think the appended patch
> > would be better.
> 
> That's right, please take it over.

OK, below is an "official" version.  Can you please double check if it fixes
the problem for you?

Rafael

---
From: Rafael J. Wysocki <rjw@xxxxxxx>
Subject: PM / Runtime: Fix loops in pm_runtime_clk_notify()

The loops over connection ID strings in pm_runtime_clk_notify()
should actually iterate over the strings and not over the elements
of the first of them, so make those loops behave as appropriate.

This fixes a regression introduced by commit 600b776eb39a13a28b090
(OMAP1 / PM: Use generic clock manipulation routines for runtime PM).

Reported-by: Janusz Krzysztofik <jkrzyszt@xxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
 drivers/base/power/clock_ops.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

Index: linux-2.6/drivers/base/power/clock_ops.c
===================================================================
--- linux-2.6.orig/drivers/base/power/clock_ops.c
+++ linux-2.6/drivers/base/power/clock_ops.c
@@ -291,7 +291,7 @@ static int pm_runtime_clk_notify(struct
 {
 	struct pm_clk_notifier_block *clknb;
 	struct device *dev = data;
-	char *con_id;
+	char **con_id;
 	int error;
 
 	dev_dbg(dev, "%s() %ld\n", __func__, action);
@@ -309,8 +309,8 @@ static int pm_runtime_clk_notify(struct
 
 		dev->pwr_domain = clknb->pwr_domain;
 		if (clknb->con_ids[0]) {
-			for (con_id = clknb->con_ids[0]; *con_id; con_id++)
-				pm_runtime_clk_add(dev, con_id);
+			for (con_id = clknb->con_ids; *con_id; con_id++)
+				pm_runtime_clk_add(dev, *con_id);
 		} else {
 			pm_runtime_clk_add(dev, NULL);
 		}
@@ -380,7 +380,7 @@ static int pm_runtime_clk_notify(struct
 {
 	struct pm_clk_notifier_block *clknb;
 	struct device *dev = data;
-	char *con_id;
+	char **con_id;
 
 	dev_dbg(dev, "%s() %ld\n", __func__, action);
 
@@ -389,16 +389,16 @@ static int pm_runtime_clk_notify(struct
 	switch (action) {
 	case BUS_NOTIFY_ADD_DEVICE:
 		if (clknb->con_ids[0]) {
-			for (con_id = clknb->con_ids[0]; *con_id; con_id++)
-				enable_clock(dev, con_id);
+			for (con_id = clknb->con_ids; *con_id; con_id++)
+				enable_clock(dev, *con_id);
 		} else {
 			enable_clock(dev, NULL);
 		}
 		break;
 	case BUS_NOTIFY_DEL_DEVICE:
 		if (clknb->con_ids[0]) {
-			for (con_id = clknb->con_ids[0]; *con_id; con_id++)
-				disable_clock(dev, con_id);
+			for (con_id = clknb->con_ids; *con_id; con_id++)
+				disable_clock(dev, *con_id);
 		} else {
 			disable_clock(dev, NULL);
 		}
--
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