linux-kernel - Re: [PATCH 2/2] drm/ast: Fix connector leak during driver unload

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Date:   Thu, 29 Nov 2018 09:40:53 +1000
From:   Dave Airlie <airlied@...il.com>
To:     sbobroff@...ux.ibm.com
Cc:     Dave Airlie <airlied@...hat.com>, Dave Airlie <airlied@...ux.ie>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] drm/ast: Fix connector leak during driver unload

On Mon, 5 Nov 2018 at 15:59, Sam Bobroff <sbobroff@...ux.ibm.com> wrote:
>
> When unloading the ast driver, a warning message is printed by
> drm_mode_config_cleanup() because a reference is still held to one of
> the drm_connector structs.
>
> Correct this by calling drm_framebuffer_remove() in
> ast_fbdev_destroy().
>
> Signed-off-by: Sam Bobroff <sbobroff@...ux.ibm.com>
> ---
>  drivers/gpu/drm/ast/ast_fb.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
> index 0cd827e11fa2..655372ea81e9 100644
> --- a/drivers/gpu/drm/ast/ast_fb.c
> +++ b/drivers/gpu/drm/ast/ast_fb.c
> @@ -263,6 +263,10 @@ static void ast_fbdev_destroy(struct drm_device *dev,
>  {
>         struct ast_framebuffer *afb = &afbdev->afb;
>
> +       /* drm_framebuffer_remove() expects us to hold a ref, which it
> +        * will drop, so take one: */
> +       drm_framebuffer_get(&afb->base);
> +       drm_framebuffer_remove(&afb->base);

This doesn't seem corret, no other driver does this pattern, and I
can't believe ast is special here.

The get just doesn't make sense.

Dave.