linux-kernel - [PATCH 5.7 095/265] bus: ti-sysc: Ignore clockactivity unless specified as a quirk

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Date:   Mon, 29 Jun 2020 11:15:28 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Tony Lindgren <tony@...mide.com>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Tomi Valkeinen <tomi.valkeinen@...com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.7 095/265] bus: ti-sysc: Ignore clockactivity unless specified as a quirk

From: Tony Lindgren <tony@...mide.com>

[ Upstream commit 08b91dd6e547467fad61a7c201ff71080d7ad65a ]

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>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 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
index a3a2c269e9ad7..4f640a635ded1 100644
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -988,10 +988,13 @@ 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 */
-- 
2.25.1