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From:   Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Date:   Tue, 23 Jun 2020 18:35:40 +0200
Message-ID: <CAMeQTsYAomJnjc6eVnDxQL+FC3nG+n1ZDqUPGgDpU=tt9d+JMA@mail.gmail.com>
Subject: Re: [PATCH] drm/gma500: Fix direction check in psb_accel_2d_copy()
To:     Denis Efremov <efremov@linux.com>
Cc:     Alan Cox <alan@linux.intel.com>, David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        stable@vger.kernel.org
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On Mon, Jun 22, 2020 at 10:45 PM Denis Efremov <efremov@linux.com> wrote:
>
> psb_accel_2d_copy() checks direction PSB_2D_COPYORDER_BR2TL twice.
> Based on psb_accel_2d_copy_direction() results, PSB_2D_COPYORDER_TL2BR
> should be checked instead in the second direction check.
>
> Fixes: 4d8d096e9ae8 ("gma500: introduce the framebuffer support code")
> Cc: stable@vger.kernel.org
> Signed-off-by: Denis Efremov <efremov@linux.com>
> ---
>  drivers/gpu/drm/gma500/accel_2d.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/gma500/accel_2d.c b/drivers/gpu/drm/gma500/accel_2d.c
> index adc0507545bf..8dc86aac54d2 100644
> --- a/drivers/gpu/drm/gma500/accel_2d.c
> +++ b/drivers/gpu/drm/gma500/accel_2d.c
> @@ -179,8 +179,8 @@ static int psb_accel_2d_copy(struct drm_psb_private *dev_priv,
>                 src_x += size_x - 1;
>                 dst_x += size_x - 1;
>         }
> -       if (direction == PSB_2D_COPYORDER_BR2TL ||
> -           direction == PSB_2D_COPYORDER_BL2TR) {
> +       if (direction == PSB_2D_COPYORDER_BL2TR ||
> +           direction == PSB_2D_COPYORDER_TL2BR) {

Hi Denis,

Sorry, I don't follow. The code seems already correct to me.

src_x and dst_x gets adjusted when going from right to left
src_y and dst_y gets adjusted when going from bottom to top.

PSB_2D_COPYORDER_TL2BR needs no adjustment because it is the normal
blit direction.

Thanks
Patrik

>                 src_y += size_y - 1;
>                 dst_y += size_y - 1;
>         }
> --
> 2.26.2
>