On Fri, Sep 15, 2017 at 04:04:03PM +0200, Romain Izard wrote:
> 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>
I faced the same issue because of the use of regmap_read_poll_timeout
when timekeeping is not ready.
Ludovic
> ---
> 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 = {
> --
> 2.11.0
>
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