linux-kernel - [PATCH 3/5] bus: ti-sysc: Ignore clockactivity unless specified as a quirk

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Date:   Sun, 31 May 2020 12:39:39 -0700
From:   Tony Lindgren <tony@...mide.com>
To:     linux-omap@...r.kernel.org
Cc:     "Andrew F . Davis" <afd@...com>, Dave Gerlach <d-gerlach@...com>,
        Faiz Abbas <faiz_abbas@...com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Grygorii Strashko <grygorii.strashko@...com>,
        Keerthy <j-keerthy@...com>, Nishanth Menon <nm@...com>,
        Peter Ujfalusi <peter.ujfalusi@...com>,
        Roger Quadros <rogerq@...com>, Suman Anna <s-anna@...com>,
        Tero Kristo <t-kristo@...com>, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Tomi Valkeinen <tomi.valkeinen@...com>,
        dri-devel@...ts.freedesktop.org
Subject: [PATCH 3/5] bus: ti-sysc: Ignore clockactivity unless specified as a quirk

We must ignore the clockactivity bit for most modules and not set it
unless specified for the module with SYSC_QUIRK_USE_CLOCKACT. Otherwise
the interface clock can be automatically gated constantly causing
unexpected performance issues.

Fixes: ae9ae12e9daa ("bus: ti-sysc: Handle clockactivity for enable and disable")
Cc: Laurent Pinchart <laurent.pinchart@...asonboard.com>
Cc: Tomi Valkeinen <tomi.valkeinen@...com>
Signed-off-by: Tony Lindgren <tony@...mide.com>
---
 drivers/bus/ti-sysc.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -989,10 +989,13 @@ static int sysc_enable_module(struct device *dev)
 	regbits = ddata->cap->regbits;
 	reg = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);
 
-	/* Set CLOCKACTIVITY, we only use it for ick */
+	/*
+	 * Set CLOCKACTIVITY, we only use it for ick. And we only configure it
+	 * based on the SYSC_QUIRK_USE_CLOCKACT flag, not based on the hardware
+	 * capabilities. See the old HWMOD_SET_DEFAULT_CLOCKACT flag.
+	 */
 	if (regbits->clkact_shift >= 0 &&
-	    (ddata->cfg.quirks & SYSC_QUIRK_USE_CLOCKACT ||
-	     ddata->cfg.sysc_val & BIT(regbits->clkact_shift)))
+	    (ddata->cfg.quirks & SYSC_QUIRK_USE_CLOCKACT))
 		reg |= SYSC_CLOCACT_ICK << regbits->clkact_shift;
 
 	/* Set SIDLE mode */
-- 
2.26.2