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Subject[PATCH v2 1/2] pm: at91: pm_slowclock: fix suspend/resume hang up in timeouts
Removed timeout on XTAL, PLL lock and Master Clock Ready, hang if
something went wrong instead of continuing in unknown condition. There
is not much we can do if a PLL lock never ends, we are running in SRAM
and we will not be able to connect back the sdram or ddram in order to
be able to fire up a message or just panic.

As a bonus, not decounting the timeout register in slow clock mode
reduce cumulated suspend time and resume time from ~17ms to ~15ms.

Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
---
arch/arm/mach-at91/pm_slowclock.S | 33 ++++-----------------------------
1 file changed, 4 insertions(+), 29 deletions(-)

diff --git a/arch/arm/mach-at91/pm_slowclock.S b/arch/arm/mach-at91/pm_slowclock.S
index 2001877..79dfdbe 100644
--- a/arch/arm/mach-at91/pm_slowclock.S
+++ b/arch/arm/mach-at91/pm_slowclock.S
@@ -34,11 +34,6 @@
*/
#undef SLOWDOWN_MASTER_CLOCK

-#define MCKRDY_TIMEOUT 1000
-#define MOSCRDY_TIMEOUT 1000
-#define PLLALOCK_TIMEOUT 1000
-#define PLLBLOCK_TIMEOUT 1000
-
pmc .req r0
sdramc .req r1
ramc1 .req r2
@@ -50,56 +45,36 @@ tmp2 .req r5
* Wait until master clock is ready (after switching master clock source)
*/
.macro wait_mckrdy
- mov tmp2, #MCKRDY_TIMEOUT
-1: sub tmp2, tmp2, #1
- cmp tmp2, #0
- beq 2f
- ldr tmp1, [pmc, #AT91_PMC_SR]
+1: ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_MCKRDY
beq 1b
-2:
.endm

/*
* Wait until master oscillator has stabilized.
*/
.macro wait_moscrdy
- mov tmp2, #MOSCRDY_TIMEOUT
-1: sub tmp2, tmp2, #1
- cmp tmp2, #0
- beq 2f
- ldr tmp1, [pmc, #AT91_PMC_SR]
+1: ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_MOSCS
beq 1b
-2:
.endm

/*
* Wait until PLLA has locked.
*/
.macro wait_pllalock
- mov tmp2, #PLLALOCK_TIMEOUT
-1: sub tmp2, tmp2, #1
- cmp tmp2, #0
- beq 2f
- ldr tmp1, [pmc, #AT91_PMC_SR]
+1: ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_LOCKA
beq 1b
-2:
.endm

/*
* Wait until PLLB has locked.
*/
.macro wait_pllblock
- mov tmp2, #PLLBLOCK_TIMEOUT
-1: sub tmp2, tmp2, #1
- cmp tmp2, #0
- beq 2f
- ldr tmp1, [pmc, #AT91_PMC_SR]
+1: ldr tmp1, [pmc, #AT91_PMC_SR]
tst tmp1, #AT91_PMC_LOCKB
beq 1b
-2:
.endm

.text
--
2.1.4


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