linux-kernel - [PATCH v1 4/4] media: staging: tegra-vde: Power-cycle hardware on probe

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]

Date:   Fri, 15 May 2020 00:08:47 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Hans Verkuil <hverkuil@...all.nl>,
        Dan Carpenter <dan.carpenter@...cle.com>
Cc:     linux-media@...r.kernel.org, linux-tegra@...r.kernel.org,
        devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org
Subject: [PATCH v1 4/4] media: staging: tegra-vde: Power-cycle hardware on probe

VDE partition is left turned ON after bootloader on most devices, hence
let's ensure that it's turned OFF in order to lower power leakage while
hardware is idling by turning it ON and OFF during of the driver's probe.

Signed-off-by: Dmitry Osipenko <digetx@...il.com>
---
 drivers/staging/media/tegra-vde/vde.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/media/tegra-vde/vde.c
index b64e35b86fb4..3be96c36bf43 100644
--- a/drivers/staging/media/tegra-vde/vde.c
+++ b/drivers/staging/media/tegra-vde/vde.c
@@ -1068,6 +1068,14 @@ static int tegra_vde_probe(struct platform_device *pdev)
 	pm_runtime_use_autosuspend(dev);
 	pm_runtime_set_autosuspend_delay(dev, 300);
 
+	/*
+	 * VDE partition may be left ON after bootloader, hence let's
+	 * power-cycle it in order to put hardware into a predictable lower
+	 * power state.
+	 */
+	pm_runtime_get_sync(dev);
+	pm_runtime_put(dev);
+
 	return 0;
 
 err_deinit_iommu:
-- 
2.26.0