linux-kernel - [ 76/82] ACPI battery: only refresh the sysfs files when pertinent information changes

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

Message-Id: <20120607040347.636736493@linuxfoundation.org>
Date:	Thu, 07 Jun 2012 13:04:52 +0900
From:	Greg KH <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk, Andy Whitcroft <apw@...onical.com>,
	Ralf Jung <post@...fj.de>, Len Brown <len.brown@...el.com>
Subject: [ 76/82] ACPI battery: only refresh the sysfs files when pertinent information changes

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Whitcroft <apw@...onical.com>

commit c5971456964290da7e98222892797b71ef793e62 upstream.

We only need to regenerate the sysfs files when the capacity units
change, avoid the update otherwise.

The origin of this issue is dates way back to 2.6.38:
da8aeb92d4853f37e281f11fddf61f9c7d84c3cd
(ACPI / Battery: Update information on info notification and resume)

Signed-off-by: Andy Whitcroft <apw@...onical.com>
Tested-by: Ralf Jung <post@...fj.de>
Signed-off-by: Len Brown <len.brown@...el.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/acpi/battery.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -643,11 +643,19 @@ static int acpi_battery_update(struct ac
 
 static void acpi_battery_refresh(struct acpi_battery *battery)
 {
+	int power_unit;
+
 	if (!battery->bat.dev)
 		return;
 
+	power_unit = battery->power_unit;
+
 	acpi_battery_get_info(battery);
-	/* The battery may have changed its reporting units. */
+
+	if (power_unit == battery->power_unit)
+		return;
+
+	/* The battery has changed its reporting units. */
 	sysfs_remove_battery(battery);
 	sysfs_add_battery(battery);
 }


--
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/