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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Sergey Shtylyov <s.shtylyov@omprussia.ru>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Jens Axboe <axboe@kernel.dk>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 231/425] pata_arasan_cf: fix IRQ check
Date:   Thu, 20 May 2021 11:20:00 +0200
Message-Id: <20210520092139.027604008@linuxfoundation.org>
In-Reply-To: <20210520092131.308959589@linuxfoundation.org>
References: <20210520092131.308959589@linuxfoundation.org>
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From: Sergey Shtylyov <s.shtylyov@omprussia.ru>

[ Upstream commit c7e8f404d56b99c80990b19a402c3f640d74be05 ]

The driver's probe() method is written as if platform_get_irq() returns 0
on error, while actually it returns a negative error code (with all the
other values considered valid IRQs). Rewrite the driver's IRQ checking code
to pass the positive IRQ #s to ata_host_activate(), propagate upstream
-EPROBE_DEFER, and set up the driver to polling mode on (negative) errors
and IRQ0 (libata treats IRQ #0 as a polling mode anyway)...

Fixes: a480167b23ef ("pata_arasan_cf: Adding support for arasan compact flash host controller")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/ata/pata_arasan_cf.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/ata/pata_arasan_cf.c b/drivers/ata/pata_arasan_cf.c
index ebecab8c3f36..7c1c399450f3 100644
--- a/drivers/ata/pata_arasan_cf.c
+++ b/drivers/ata/pata_arasan_cf.c
@@ -817,12 +817,19 @@ static int arasan_cf_probe(struct platform_device *pdev)
 	else
 		quirk = CF_BROKEN_UDMA; /* as it is on spear1340 */
 
-	/* if irq is 0, support only PIO */
-	acdev->irq = platform_get_irq(pdev, 0);
-	if (acdev->irq)
+	/*
+	 * If there's an error getting IRQ (or we do get IRQ0),
+	 * support only PIO
+	 */
+	ret = platform_get_irq(pdev, 0);
+	if (ret > 0) {
+		acdev->irq = ret;
 		irq_handler = arasan_cf_interrupt;
-	else
+	} else	if (ret == -EPROBE_DEFER) {
+		return ret;
+	} else	{
 		quirk |= CF_BROKEN_MWDMA | CF_BROKEN_UDMA;
+	}
 
 	acdev->pbase = res->start;
 	acdev->vbase = devm_ioremap_nocache(&pdev->dev, res->start,
-- 
2.30.2