diff options
Diffstat (limited to 'arch/arm/mach-imx/pm-imx6q.c')
| -rw-r--r-- | arch/arm/mach-imx/pm-imx6q.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/arch/arm/mach-imx/pm-imx6q.c b/arch/arm/mach-imx/pm-imx6q.c index aecd9f8037e0..9d47adc078aa 100644 --- a/arch/arm/mach-imx/pm-imx6q.c +++ b/arch/arm/mach-imx/pm-imx6q.c @@ -156,10 +156,16 @@ int imx6q_set_lpm(enum mxc_cpu_pwr_mode mode) } /* - * Unmask the always pending IOMUXC interrupt #32 as wakeup source to - * deassert dsm_request signal, so that we can ensure dsm_request - * is not asserted when we're going to write CLPCR register to set LPM. - * After setting up LPM bits, we need to mask this wakeup source. + * ERR007265: CCM: When improper low-power sequence is used, + * the SoC enters low power mode before the ARM core executes WFI. + * + * Software workaround: + * 1) Software should trigger IRQ #32 (IOMUX) to be always pending + * by setting IOMUX_GPR1_GINT. + * 2) Software should then unmask IRQ #32 in GPC before setting CCM + * Low-Power mode. + * 3) Software should mask IRQ #32 right after CCM Low-Power mode + * is set (set bits 0-1 of CCM_CLPCR). */ iomuxc_irq_desc = irq_to_desc(32); imx_gpc_irq_unmask(&iomuxc_irq_desc->irq_data); @@ -219,6 +225,8 @@ void __init imx6q_pm_init(void) WARN_ON(!ccm_base); /* + * This is for SW workaround step #1 of ERR007265, see comments + * in imx6q_set_lpm for details of this errata. * Force IOMUXC irq pending, so that the interrupt to GPC can be * used to deassert dsm_request signal when the signal gets * asserted unexpectedly. |