[PATCH v6 1/3] clk: at91: pmc: Wait for clocks when resuming

From: Romain Izard
Date: Mon Dec 11 2017 - 11:58:27 EST


Wait for the syncronization of all clocks when resuming, not only the
UPLL clock. Do not use regmap_read_poll_timeout, as it will call BUG()
when interrupts are masked, which is the case in here.

Signed-off-by: Romain Izard <romain.izard.pro@xxxxxxxxx>
Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
---
drivers/clk/at91/pmc.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
index 775af473fe11..5c2b26de303e 100644
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c
@@ -107,10 +107,20 @@ static int pmc_suspend(void)
return 0;
}

+static bool pmc_ready(unsigned int mask)
+{
+ unsigned int status;
+
+ regmap_read(pmcreg, AT91_PMC_SR, &status);
+
+ return ((status & mask) == mask) ? 1 : 0;
+}
+
static void pmc_resume(void)
{
- int i, ret = 0;
+ int i;
u32 tmp;
+ u32 mask = AT91_PMC_MCKRDY | AT91_PMC_LOCKA;

regmap_read(pmcreg, AT91_PMC_MCKR, &tmp);
if (pmc_cache.mckr != tmp)
@@ -134,13 +144,11 @@ static void pmc_resume(void)
AT91_PMC_PCR_CMD);
}

- if (pmc_cache.uckr & AT91_PMC_UPLLEN) {
- ret = regmap_read_poll_timeout(pmcreg, AT91_PMC_SR, tmp,
- !(tmp & AT91_PMC_LOCKU),
- 10, 5000);
- if (ret)
- pr_crit("USB PLL didn't lock when resuming\n");
- }
+ if (pmc_cache.uckr & AT91_PMC_UPLLEN)
+ mask |= AT91_PMC_LOCKU;
+
+ while (!pmc_ready(mask))
+ cpu_relax();
}

static struct syscore_ops pmc_syscore_ops = {
--
2.14.1