linux-kernel - [RESEND PATCH v2 2/5] backlight: pwm_bl: Add device link for pwm

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Date:   Mon, 16 Oct 2017 18:06:37 +0800
From:   Jeffy Chen <jeffy.chen@...k-chips.com>
To:     linux-kernel@...r.kernel.org
Cc:     dmitry.torokhov@...il.com, heiko@...ech.de,
        briannorris@...omium.org, rjw@...ysocki.net, dianders@...omium.org,
        tfiga@...omium.org, broonie@...nel.org, seanpaul@...omium.org,
        Jeffy Chen <jeffy.chen@...k-chips.com>,
        linux-pwm@...r.kernel.org, linux-fbdev@...r.kernel.org,
        Daniel Thompson <daniel.thompson@...aro.org>,
        Thierry Reding <thierry.reding@...il.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        dri-devel@...ts.freedesktop.org, Jingoo Han <jingoohan1@...il.com>,
        Lee Jones <lee.jones@...aro.org>
Subject: [RESEND PATCH v2 2/5] backlight: pwm_bl: Add device link for pwm_bl and pwm

When the pwm driver is unbound, the pwm_bl driver would still hold a
reference to that pwm, and crash the kernel later(if someone trying
to access that invalid pwm).

Add a device link to avoid this.

Signed-off-by: Jeffy Chen <jeffy.chen@...k-chips.com>
---

Changes in v2: None

 drivers/video/backlight/pwm_bl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 9bd17682655a..a76f147a26e7 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -328,6 +328,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 		goto err_alloc;
 	}
 
+	device_link_add(&pdev->dev, pb->pwm->chip->dev, DL_FLAG_AUTOREMOVE);
+
 	dev_dbg(&pdev->dev, "got pwm for backlight\n");
 
 	/*
-- 
2.11.0