From: Tony Lindgren <tony@atomide.com>
To: Tero Kristo <t-kristo@ti.com>
Cc: linux-omap@vger.kernel.org, linux-clk@vger.kernel.org,
sboyd@codeaurora.org, mturquette@baylibre.com, paul@pwsan.com,
linux-arm-kernel@lists.infradead.org
Subject: Re: [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
WARNING: multiple messages have this Message-ID (diff)
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
next prev parent reply other threads:[~2015-12-03 16:48 UTC|newest]
Thread overview: 12+ 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 14:43 ` Tero Kristo
2015-11-30 14:43 ` Tero Kristo
2015-11-30 19:35 ` Stephen Boyd
2015-11-30 19:35 ` Stephen Boyd
2015-12-03 16:48 ` Tony Lindgren [this message]
2015-12-03 16:48 ` Tony Lindgren
2015-12-11 8:43 ` Tero Kristo
2015-12-11 8:43 ` Tero Kristo
2015-12-11 8:43 ` Tero Kristo
2015-12-11 16:55 ` Tony Lindgren
2015-12-11 16:55 ` Tony Lindgren
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