diff mbox

[11/12] OMAP2/3: SRAM: add comment about crashes during a TLB miss

Message ID 20101214063453.21555.15306.stgit@twilight.localdomain (mailing list archive)
State New, archived
Delegated to: Paul Walmsley
Headers show

Commit Message

Paul Walmsley Dec. 14, 2010, 6:34 a.m. UTC
None
diff mbox

Patch

diff --git a/arch/arm/mach-omap2/sram242x.S b/arch/arm/mach-omap2/sram242x.S
index 92e6e1a..6d88cee 100644
--- a/arch/arm/mach-omap2/sram242x.S
+++ b/arch/arm/mach-omap2/sram242x.S
@@ -21,6 +21,12 @@ 
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  * MA 02111-1307 USA
+ *
+ * Richard Woodruff notes that any changes to this code must be carefully
+ * audited and tested to ensure that they don't cause a TLB miss while
+ * the SDRAM is inaccessible.  Such a situation will crash the system
+ * since it will cause the ARM MMU to attempt to walk the page tables.
+ * These crashes may be intermittent.
  */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
diff --git a/arch/arm/mach-omap2/sram243x.S b/arch/arm/mach-omap2/sram243x.S
index ab49736..2f104a6 100644
--- a/arch/arm/mach-omap2/sram243x.S
+++ b/arch/arm/mach-omap2/sram243x.S
@@ -21,6 +21,12 @@ 
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  * MA 02111-1307 USA
+ *
+ * Richard Woodruff notes that any changes to this code must be carefully
+ * audited and tested to ensure that they don't cause a TLB miss while
+ * the SDRAM is inaccessible.  Such a situation will crash the system
+ * since it will cause the ARM MMU to attempt to walk the page tables.
+ * These crashes may be intermittent.
  */
 #include <linux/linkage.h>
 #include <asm/assembler.h>
diff --git a/arch/arm/mach-omap2/sram34xx.S b/arch/arm/mach-omap2/sram34xx.S
index 3637274..43f67f5 100644
--- a/arch/arm/mach-omap2/sram34xx.S
+++ b/arch/arm/mach-omap2/sram34xx.S
@@ -104,6 +104,12 @@ 
  * touching the SDRAM.  Until that time, users who know that their use case
  * can satisfy the above requirement can enable the CONFIG_OMAP3_SDRC_AC_TIMING
  * option.
+ *
+ * Richard Woodruff notes that any changes to this code must be carefully
+ * audited and tested to ensure that they don't cause a TLB miss while
+ * the SDRAM is inaccessible.  Such a situation will crash the system
+ * since it will cause the ARM MMU to attempt to walk the page tables.
+ * These crashes may be intermittent.
  */
 ENTRY(omap3_sram_configure_core_dpll)
 	stmfd	sp!, {r1-r12, lr}	@ store regs to stack