Linux RTC
 help / color / mirror / Atom feed
From: Akashdeep Kaur <a-kaur@ti.com>
To: <praneeth@ti.com>, <nm@ti.com>, <vigneshr@ti.com>,
	<alexandre.belloni@bootlin.com>, <linux-rtc@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <sebin.francis@ti.com>
Cc: <s-tripathi1@ti.com>, <vishalm@ti.com>, <k-willis@ti.com>,
	<a-kaur@ti.com>
Subject: [PATCH 2/2] rtc: ti-k3: Mark RTC time as invalid without battery backup
Date: Wed, 21 Oct 2026 09:54:35 +0530	[thread overview]
Message-ID: <20261021042435.3895543-3-a-kaur@ti.com> (raw)
In-Reply-To: <20261021042435.3895543-1-a-kaur@ti.com>

TI K3 RTC typically has no battery backup. Prevent HCTOSYS from
overwriting valid system time (established by bootloader or early
NTP sync) with invalid RTC value.

Signed-off-by: Akashdeep Kaur <a-kaur@ti.com>
---
 drivers/rtc/rtc-ti-k3.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/rtc/rtc-ti-k3.c b/drivers/rtc/rtc-ti-k3.c
index 8df00319cb6b..99fdf1192675 100644
--- a/drivers/rtc/rtc-ti-k3.c
+++ b/drivers/rtc/rtc-ti-k3.c
@@ -613,6 +613,13 @@ static int ti_k3_rtc_probe(struct platform_device *pdev)
 	else
 		device_set_wakeup_capable(dev, true);
 
+	/*
+	 * TI K3 RTC has no battery backup in typical configurations.
+	 * Mark time as invalid to prevent hctosys from overwriting
+	 * correct system time (from bootloader/NTP) with invalid RTC value.
+	 */
+	priv->rtc_dev->time_is_valid = false;
+
 	ret = devm_rtc_register_device(priv->rtc_dev);
 	if (ret)
 		return ret;
-- 
2.34.1


  parent reply	other threads:[~2026-10-21  4:25 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-21  4:24 [PATCH 0/2] rtc: Prevent hctosys from using invalid RTC time Akashdeep Kaur
2026-10-21  4:24 ` [PATCH 1/2] rtc: Add flag for dynamic hctosys control Akashdeep Kaur
2026-10-21  4:37   ` sashiko-bot
2026-10-21  5:25     ` Akashdeep Kaur
2026-10-21  4:24 ` Akashdeep Kaur [this message]
2026-10-21  4:37   ` [PATCH 2/2] rtc: ti-k3: Mark RTC time as invalid without battery backup sashiko-bot
2026-10-21  7:13 ` [PATCH 0/2] rtc: Prevent hctosys from using invalid RTC time Alexandre Belloni

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20261021042435.3895543-3-a-kaur@ti.com \
    --to=a-kaur@ti.com \
    --cc=alexandre.belloni@bootlin.com \
    --cc=k-willis@ti.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rtc@vger.kernel.org \
    --cc=nm@ti.com \
    --cc=praneeth@ti.com \
    --cc=s-tripathi1@ti.com \
    --cc=sebin.francis@ti.com \
    --cc=vigneshr@ti.com \
    --cc=vishalm@ti.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox