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From: tony@atomide•com (Tony Lindgren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] clk: ti: omap5+: dpll: implement errata i810
Date: Thu, 3 Dec 2015 08:48:18 -0800	[thread overview]
Message-ID: <20151203164817.GT23396@atomide.com> (raw)
In-Reply-To: <1448894605-30097-1-git-send-email-t-kristo@ti.com>

* Tero Kristo <t-kristo@ti•com> [151130 06:44]:
> +	/*
> +	 * Errata i810 - DPLL controller can get stuck while transitioning
> +	 * to a power saving state. Software must ensure the DPLL can not
> +	 * transition to a low power state while changing M/N values.
> +	 * Easiest way to accomplish this is to prevent DPLL autoidle
> +	 * before doing the M/N re-program.
> +	 */
> +	errata_i810 = ti_clk_get_features()->flags & TI_CLK_ERRATA_I810;
> +
> +	if (errata_i810) {
> +		ai = omap3_dpll_autoidle_read(clk);
> +		if (ai) {
> +			omap3_dpll_deny_idle(clk);
> +
> +			/* OCP barrier */
> +			omap3_dpll_autoidle_read(clk);
> +		}
> +	}

Should we just do this unconditionally? It seems like disabling the
autoidle always before reprogramming is a good idea.

Regards,

Tony

  parent reply	other threads:[~2015-12-03 16:48 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-30 14:43 [PATCH] clk: ti: omap5+: dpll: implement errata i810 Tero Kristo
2015-11-30 19:35 ` Stephen Boyd
2015-12-03 16:48 ` Tony Lindgren [this message]
2015-12-11  8:43   ` Tero Kristo
2015-12-11 16:55     ` Tony Lindgren

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