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From:   Heiko Stuebner <heiko@sntech.de>
To:     Colin King <colin.king@canonical.com>,
        Chris Zhong <zyw@rock-chips.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Sandy Huang <hjc@rock-chips.com>,
        linux-arm-kernel@lists.infradead.org,
        Guenter Roeck <groeck@chromium.org>,
        Sean Paul <seanpaul@chromium.org>,
        David Airlie <airlied@linux.ie>,
        dri-devel@lists.freedesktop.org, linux-rockchip@lists.infradead.org
Cc:     Heiko Stuebner <heiko@sntech.de>, kernel-janitors@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drm/rockchip: cdn-dp: fix sign extension on an int multiply for a u64 result
Date:   Fri, 28 May 2021 20:55:53 +0200
Message-Id: <162222814865.2904787.9681017201633439176.b4-ty@sntech.de>
In-Reply-To: <20200915162049.36434-1-colin.king@canonical.com>
References: <20200915162049.36434-1-colin.king@canonical.com>
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On Tue, 15 Sep 2020 17:20:49 +0100, Colin King wrote:
> The variable bit_per_pix is a u8 and is promoted in the multiplication
> to an int type and then sign extended to a u64. If the result of the
> int multiplication is greater than 0x7fffffff then the upper 32 bits will
> be set to 1 as a result of the sign extension. Avoid this by casting
> tu_size_reg to u64 to avoid sign extension and also a potential overflow.

Applied, thanks!

[1/1] drm/rockchip: cdn-dp: fix sign extension on an int multiply for a u64 result
      commit: ce0cb93a5adb283f577cd4661f511047b5e39028

Best regards,
-- 
Heiko Stuebner <heiko@sntech.de>