From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1423D19465 for ; Mon, 16 Oct 2023 08:44:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1AVkeDp9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B686C433C9; Mon, 16 Oct 2023 08:44:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1697445874; bh=sIYxOth2Dg98zUHYXpL8BzT/jN19Sbn0YRrYXgXkkVE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1AVkeDp9hgyng5834tOX58+kjFL3Sj+kI6rRXe/mUY3H/WoR+n7xwFlcleM0NvMCB rg5C2EQbyi55jmWLG9r4CmBrGxg6dOOkFVZW37ST79ZCRqzbBJS1OzC404x+DkD2fl 5EGrTRmiXOeAKRJ7Txj8xLDBIp7OIcDHLwIG10Mg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dmitry Baryshkov , Nia Espera , Abhinav Kumar , Sasha Levin Subject: [PATCH 5.15 021/102] drm/msm/dpu: change _dpu_plane_calc_bw() to use u64 to avoid overflow Date: Mon, 16 Oct 2023 10:40:20 +0200 Message-ID: <20231016083954.252327031@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231016083953.689300946@linuxfoundation.org> References: <20231016083953.689300946@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Abhinav Kumar [ Upstream commit 95e681ca3b65e4ce3d2537b47672d787b7d30375 ] _dpu_plane_calc_bw() uses integer variables to calculate the bandwidth used during plane bandwidth calculations. However for high resolution displays this overflows easily and leads to below errors [dpu error]crtc83 failed performance check -7 Promote the intermediate variables to u64 to avoid overflow. changes in v2: - change to u64 where actually needed in the math Fixes: c33b7c0389e1 ("drm/msm/dpu: add support for clk and bw scaling for display") Reviewed-by: Dmitry Baryshkov Reported-by: Nia Espera Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/32 Tested-by: Nia Espera Patchwork: https://patchwork.freedesktop.org/patch/556288/ Link: https://lore.kernel.org/r/20230908012616.20654-1-quic_abhinavk@quicinc.com Signed-off-by: Abhinav Kumar Signed-off-by: Sasha Levin --- drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c index 59390dc3d1b8c..9c30ab106b0a1 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c @@ -158,6 +158,7 @@ static void _dpu_plane_calc_bw(struct drm_plane *plane, const struct dpu_format *fmt = NULL; struct dpu_kms *dpu_kms = _dpu_plane_get_kms(plane); int src_width, src_height, dst_height, fps; + u64 plane_pixel_rate, plane_bit_rate; u64 plane_prefill_bw; u64 plane_bw; u32 hw_latency_lines; @@ -180,13 +181,12 @@ static void _dpu_plane_calc_bw(struct drm_plane *plane, scale_factor = src_height > dst_height ? mult_frac(src_height, 1, dst_height) : 1; - plane_bw = - src_width * mode->vtotal * fps * fmt->bpp * - scale_factor; + plane_pixel_rate = src_width * mode->vtotal * fps; + plane_bit_rate = plane_pixel_rate * fmt->bpp; - plane_prefill_bw = - src_width * hw_latency_lines * fps * fmt->bpp * - scale_factor * mode->vtotal; + plane_bw = plane_bit_rate * scale_factor; + + plane_prefill_bw = plane_bw * hw_latency_lines; if ((vbp+vpw) > hw_latency_lines) do_div(plane_prefill_bw, (vbp+vpw)); -- 2.40.1