On Wed, May 02, 2012 at 02:17:45AM +0100, Yilu Mao wrote:

On 04/30/2012 09:34 PM, Catalin Marinas wrote:

quoted

On 30 April 2012 14:16, Yilu Mao[off-list ref]  wrote:

quoted

If l2x0 controller has been enabled when calling l2x0_init, the aux ctrl
register will not be saved in l2x0_saved_regs. Therefore we can not use
l2x0_saved_regs.aux_ctrl for resume later. This patch fixed the problem
by saving aux ctrl in l2x0_saved_regs just after it's being read from
the register.
And in case some bits of aux ctrl register are reserved, re-read and
save it properly after set it if l2x0 is disabled before init.

Change-Id: I54f3002274ffe9cdc667dba81e36e08f2e121467
Signed-off-by: Yilu Mao<redacted>
---
  arch/arm/mm/cache-l2x0.c |    9 +++++++++
  1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index a53fd2a..9893e58 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c

@@ -320,6 +320,13 @@ void __init l2x0_init(void __iomem *base, u32 aux_val, u32 aux_mask)
        cache_id = readl_relaxed(l2x0_base + L2X0_CACHE_ID);
        aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL);

+       /*
+        * In case l2x controller is enabled, the aux ctrl register
+        * can't be set. So the original value should be stored in
+        * the l2x0_saved_regs for restoring when resume.
+        */
+       l2x0_saved_regs.aux_ctrl = aux;

Why not move this

quoted

+
        aux&= aux_mask;
        aux |= aux_val;

@@ -364,6 +371,8 @@ void __init l2x0_init(void __iomem *base, u32 aux_val, u32 aux_mask)
                /* l2x0 controller is disabled */
                writel_relaxed(aux, l2x0_base + L2X0_AUX_CTRL);

+               /* Re-read it in case some bits are reserved. */
+               aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL);

and this

quoted

                l2x0_saved_regs.aux_ctrl = aux;

                l2x0_inv_all();

somewhere after the if block and we only read the aux once. The
comment may no longer make sense though.

I want to make it clear before I provide a new patch. :)
We can't only read once because we must read it before handle the 
aux_val and aux_mask arguments.

I was thinking about something like this:

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 361a628..fbd8903 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c

@@ -371,14 +371,15 @@ void __init l2x0_init(void __iomem *base, u32 aux_val, u32 aux_mask)
 		/* l2x0 controller is disabled */
 		writel_relaxed(aux, l2x0_base + L2X0_AUX_CTRL);
 
-		l2x0_saved_regs.aux_ctrl = aux;
-
 		l2x0_inv_all();
 
 		/* enable L2X0 */
 		writel_relaxed(1, l2x0_base + L2X0_CTRL);
 	}
 
+	aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL);
+	l2x0_saved_regs.aux_ctrl = aux;
+
 	outer_cache.inv_range = l2x0_inv_range;
 	outer_cache.clean_range = l2x0_clean_range;
 	outer_cache.flush_range = l2x0_flush_range;

-- 
Catalin