[PATCH v2 09/19] ARM: at91: make sdram/ddr register base soc independent

On 02/23/2012 09:56 AM, Nicolas Ferre :

On 02/22/2012 11:33 PM, Ryan Mallon :

quoted

On 22/02/12 20:39, Nicolas Ferre wrote:

quoted

From: Jean-Christophe PLAGNIOL-VILLARD <redacted>

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <redacted>
Acked-by: Nicolas Ferre <redacted>
---

<snip>

quoted

+void __init at91_ioremap_ramc(int id, u32 addr, u32 size)
+{
+	if (id > 1) {
+		pr_warn("%s: id > 2\n", __func__);
+		return;
+	}
+	at91_ramc_base[id] = ioremap(addr, size);
+	if (!at91_ramc_base[id])
+		pr_warn("Impossible to ioremap ramc.%d 0x%x\n", id, addr);
+}

If this fails then you will oops if you call either at91_ramc_read or
at91_ramc_write since they don't check if at91_ramc_base[id] is a valid
pointer. Either this function should panic, like the other at91_ioremap
functions, or the at91_ramc_read/write functions should check for a
valid pointer.

Yes, as you pointed out, it is done in a not-related following patch.
I will bring the code here.

quoted

Nitpick: The id check should probably also be BUG() or WARN() since it
indicates a bug in the core AT91 code. pr_warn is likely to missed and
not reported by users. Since the value is int, the check should be:

  if (id < 0 || id > 1)

Obviously the chance of this error happening are slim, but if you are
going to check and warn for it, it should be done properly :-).

Yes, I agree and modify it at the very moment.

What do you think about that:
If id is not setup properly, I try to find a way out by using id = 0...
Then, a panic is added if the iremap() fails.

--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c

@@ -200,13 +200,14 @@ void __iomem *at91_ramc_base[2];
 
 void __init at91_ioremap_ramc(int id, u32 addr, u32 size)
 {
-       if (id > 1) {
-               pr_warn("%s: id > 2\n", __func__);
-               return;
+       if (id < 0 || id > 1) {
+               WARN(1, "%s: Wrong RAM controller id (%d), set it to 0\n",
+                                                               __func__, id);
+               id = 0;
        }
        at91_ramc_base[id] = ioremap(addr, size);
        if (!at91_ramc_base[id])
-               pr_warn("Impossible to ioremap ramc.%d 0x%x\n", id, addr);
+               panic("Impossible to ioremap ramc.%d 0x%x\n", id, addr);
 }
 
 static int at91_pm_enter(suspend_state_t state)

Best regards,
-- 
Nicolas Ferre