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[v2] ARM: OMAP4: sleep: Save the complete used register stack frame

Message ID 1344495948-3490-1-git-send-email-santosh.shilimkar@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Santosh Shilimkar Aug. 9, 2012, 7:05 a.m. UTC
OMAP4 sleep entry code even though itself don't use many CPU registers
makes call to the v7_flush_dcache_all() which uses them. Since
v7_flush_dcache_all() doesn't make use of stack, the caller must take
care of the stack frame. Otherwise it will lead to corrupted stack frame.

Fix it by saving used registers.

Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
---
v2: Added comment in the code.

 arch/arm/mach-omap2/sleep44xx.S |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
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Patch

diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S
index 9f6b83d..91e71d8 100644
--- a/arch/arm/mach-omap2/sleep44xx.S
+++ b/arch/arm/mach-omap2/sleep44xx.S
@@ -56,9 +56,13 @@  ppa_por_params:
  * The restore function pointer is stored at CPUx_WAKEUP_NS_PA_ADDR_OFFSET.
  * It returns to the caller for CPU INACTIVE and ON power states or in case
  * CPU failed to transition to targeted OFF/DORMANT state.
+ *
+ * omap4_finish_suspend() calls v7_flush_dcache_all() which doesn't save
+ * stack frame and it expects the caller to take care of it. Hence the entire
+ * stack frame is saved to avoid possible stack corruption.
  */
 ENTRY(omap4_finish_suspend)
-	stmfd	sp!, {lr}
+	stmfd	sp!, {r4-r12, lr}
 	cmp	r0, #0x0
 	beq	do_WFI				@ No lowpower state, jump to WFI
 
@@ -226,7 +230,7 @@  scu_gp_clear:
 skip_scu_gp_clear:
 	isb
 	dsb
-	ldmfd	sp!, {pc}
+	ldmfd	sp!, {r4-r12, pc}
 ENDPROC(omap4_finish_suspend)
 
 /*