linux-kernel - [PATCH AUTOSEL 4.19 14/27] clocksource/drivers/sp804: Avoid error on multiple instances

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Date:   Tue,  7 Jun 2022 14:01:18 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Andre Przywara <andre.przywara@....com>,
        Robin Murphy <robin.murphy@....com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Sasha Levin <sashal@...nel.org>, tglx@...utronix.de
Subject: [PATCH AUTOSEL 4.19 14/27] clocksource/drivers/sp804: Avoid error on multiple instances

From: Andre Przywara <andre.przywara@....com>

[ Upstream commit a98399cbc1e05f7b977419f03905501d566cf54e ]

When a machine sports more than one SP804 timer instance, we only bring
up the first one, since multiple timers of the same kind are not useful
to Linux. As this is intentional behaviour, we should not return an
error message, as we do today:
===============
[    0.000800] Failed to initialize '/bus@...0000/motherboard-bus@...0000/iofpga-bus@...000000/timer@...000': -22
===============

Replace the -EINVAL return with a debug message and return 0 instead.

Also we do not reach the init function anymore if the DT node is
disabled (as this is now handled by OF_DECLARE), so remove the explicit
check for that case.

This fixes a long standing bogus error when booting ARM's fastmodels.

Signed-off-by: Andre Przywara <andre.przywara@....com>
Reviewed-by: Robin Murphy <robin.murphy@....com>
Link: https://lore.kernel.org/r/20220506162522.3675399-1-andre.przywara@arm.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@...aro.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/clocksource/timer-sp804.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/timer-sp804.c b/drivers/clocksource/timer-sp804.c
index e01222ea888f..738c50e916f7 100644
--- a/drivers/clocksource/timer-sp804.c
+++ b/drivers/clocksource/timer-sp804.c
@@ -228,6 +228,11 @@ static int __init sp804_of_init(struct device_node *np)
 	struct clk *clk1, *clk2;
 	const char *name = of_get_property(np, "compatible", NULL);
 
+	if (initialized) {
+		pr_debug("%pOF: skipping further SP804 timer device\n", np);
+		return 0;
+	}
+
 	base = of_iomap(np, 0);
 	if (!base)
 		return -ENXIO;
@@ -236,11 +241,6 @@ static int __init sp804_of_init(struct device_node *np)
 	writel(0, base + TIMER_CTRL);
 	writel(0, base + TIMER_2_BASE + TIMER_CTRL);
 
-	if (initialized || !of_device_is_available(np)) {
-		ret = -EINVAL;
-		goto err;
-	}
-
 	clk1 = of_clk_get(np, 0);
 	if (IS_ERR(clk1))
 		clk1 = NULL;
-- 
2.35.1