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Commit 0c58d0f15879856dd750223abeeb0410a0891ca2

Authored by Ranjani Vaidyanathan
1 parent 67779bf67e
Exists in imx_3.0.35_4.1.0

ENGR00318393 [iMX6x] Ensure certain CP15 registers are maintained across suspend/resume 

Many A9 errata require bits in the diagnostic control register to be set.
During a suspend/resume cycle, the A9 core may get power gated, implying
that the register needs to be maintained across a suspend/resume cycle.
Also ensure that power control register is saved/restored.

Signed-off-by: Ranjani Vaidyanathan <Ranjani.Vaidyanathan@freescale.com>

Showing 1 changed file with 16 additions and 0 deletions Side-by-side Diff

arch/arm/mach-mx6/mx6_suspend.S
Diff comments   View file @ 0c58d0f
... ... @@ -1123,6 +1123,14 @@
1123 1123 mrs r7, cpsr @ Store CPSR
1124 1124 stmfd r0!, {r4-r7}
1125 1125  
  1126 + /* Save diagnostic control register */
  1127 + mrc p15, 0, r4, c15, c0, 1 @ Diagnostic control reg
  1128 + stmfd r0!, {r4}
  1129 +
  1130 + /* Save Power control register */
  1131 + mrc p15, 0, r4, c15, c0, 0 @ Diagnostic control reg
  1132 + stmfd r0!, {r4}
  1133 +
1126 1134 /* c1 control register */
1127 1135 mrc p15, 0, r4, c1, c0, 0 @ SCTLR
1128 1136 stmfd r0!, {r4}
... ... @@ -1709,6 +1717,14 @@
1709 1717 mcr p15, 0, r5, c13, c0, 2 @ User r/w thread ID
1710 1718 mrc p15, 0, r6, c12, c0, 0 @ Secure or NS VBAR
1711 1719 msr cpsr, r7 @ store cpsr
  1720 +
  1721 + /* Restore diagnostic control register */
  1722 + ldmea r0!,{r4}
  1723 + mcr p15, 0, r4, c15, c0, 1 @ Diagnostic control reg
  1724 +
  1725 + /* Restore Power control register */
  1726 + ldmea r0!,{r4}
  1727 + mcr p15, 0, r4, c15, c0, 0 @ Diagnostic control reg
1712 1728  
1713 1729 /*
1714 1730 * Enabling MMU here. Page entry needs to be altered