linux-kernel - [PATCH] drivers/rtc/rtc-pl031.c: reset registers in init flow

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 29 Jul 2015 14:02:01 +0800
From:	Leo Yan <leo.yan@...aro.org>
To:	Linus Walleij <linus.walleij@...aro.org>,
	Alessandro Zummo <a.zummo@...ertech.it>,
	Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
	linux-arm-kernel@...ts.infradead.org, rtc-linux@...glegroups.com,
	linux-kernel@...r.kernel.org, Deepak Saxena <dsaxena@...xity.net>
Cc:	Leo Yan <leo.yan@...aro.org>
Subject: [PATCH] drivers/rtc/rtc-pl031.c: reset registers in init flow

When use rtc-pl031 for suspend test on Hisilicon's SoC Hi6220, Usually
the data register (DR) will read back as value zero. So the suspend
test code will set the match register (MR) for 10 seconds' timeout; But
there have chance later will read back some random values from DR
register; So finally miss with match value and will not trigger
waken up event anymore.

This issue can be dismissed by reset registers in initialization flow;
And this code have no harm for ST's variant.

Signed-off-by: Leo Yan <leo.yan@...aro.org>
---
 drivers/rtc/rtc-pl031.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index 99181fff..01768de 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -345,6 +345,12 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 	dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
 	dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
 
+	/* Init registers */
+	writel(0x0, ldata->base + RTC_LR);
+	writel(0x0, ldata->base + RTC_DR);
+	writel(0x0, ldata->base + RTC_IMSC);
+	writel(RTC_BIT_AI, ldata->base + RTC_ICR);
+
 	data = readl(ldata->base + RTC_CR);
 	/* Enable the clockwatch on ST Variants */
 	if (vendor->clockwatch)
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/