From nobody Tue Jun 23 09:14:05 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E759C433F5 for ; Tue, 8 Mar 2022 01:56:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244204AbiCHB5Y (ORCPT ); Mon, 7 Mar 2022 20:57:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232589AbiCHB5W (ORCPT ); Mon, 7 Mar 2022 20:57:22 -0500 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91F903F321 for ; Mon, 7 Mar 2022 17:56:26 -0800 (PST) Received: by mail-pf1-x441.google.com with SMTP id p8so16020557pfh.8 for ; Mon, 07 Mar 2022 17:56:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=2E8yu0dx7WwOCxdxcyi0NQqYJT6dBXDVWvwU57lz8KQ=; b=W4Vvp4Om53sRLaPMGoPv5Lw3SKc1neqXL4ODSGoSFaBNP4IX+aOSiXUdqKNhBI1OLU 0+beRrK3uYfg8BWDrympGzCfIi66zeCPkX0fLoNA19CS/iCRkHKA+uk2vKPPxmEzNRg4 ZM3ycFOrv6n6KdLAoJieK+TsbBUTPC4hSjCgUsCF/L8P3cmush/4rcPuiuonl0whQhyS RrozoUF0mcg0tb9JSS453Z5DAzB7TacoKp/s+nN6LuSvH76qiIA4wP0CKbCIMf4/5Y06 qbmnQIzm3JdWCFW4yi5GJwB/AoB2og/tQCSEpoApP4QAURHorqMd5zAi3SEjUurw2urR AgTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=2E8yu0dx7WwOCxdxcyi0NQqYJT6dBXDVWvwU57lz8KQ=; b=retFsTTn3vVY0GvCbySentOVXWYyeoyKrxn4sjLilxM7TWZdajaDdedUks69tJrPbi hUcHlpBeQwRvZBvn8lwB+PW2QMATHMMgIuTUSthmPsL2eyK716r2XXylXN7S8OHn88/H 6gMKLEO/6q8ikTWqJcPUxQzEAD02nVZCqdoSNjgXkwp9YkB/kZFzvWUm7YQQorY8SK3D lVzp0vHx3kCldODWMVLr3muNmIP23l8nRuhRxDXZDnAki+iKKR6EY/FoJ13zk1zVieEe e/OQ46s2RQkmOuGxjTMK/+QJbkHT0+DxxscT6WspmueAgqPw+XAqSzkowS8soQ3rx0wS iOFg== X-Gm-Message-State: AOAM531uSB1OEpydSbnPT9LrOhX5Q32tDuuoDuIGIZXnMDtmgqzSe4U9 9EkZTgTE9Qy8xEohXkTqDuc= X-Google-Smtp-Source: ABdhPJyc8tex3nzmMFhV2LyL3qoBzinohm5njUfxL/3uqEMMkFBn6X+k9KVvHtUHpCN1RBuTP/4w4Q== X-Received: by 2002:a05:6a00:a23:b0:4f6:72a8:20c7 with SMTP id p35-20020a056a000a2300b004f672a820c7mr15968222pfh.12.1646704585971; Mon, 07 Mar 2022 17:56:25 -0800 (PST) Received: from lxb-server.lan ([2605:52c0:2:32c::]) by smtp.gmail.com with ESMTPSA id mm17-20020a17090b359100b001bef7e5bdffsm619629pjb.20.2022.03.07.17.56.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Mar 2022 17:56:25 -0800 (PST) From: Yunhao Tian To: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= Cc: Yunhao Tian , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] drm/mipi-dbi: Fix max_chunk calculation in spi_transfer Date: Tue, 8 Mar 2022 09:56:11 +0800 Message-Id: <20220308015611.3007395-1-t123yh.xyz@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In __spi_validate, there's a validation that no partial transfers are accepted (xfer->len % w_size must be zero). When max_chunk is not a multiple of bpw (e.g.max_chunk =3D 65535, bpw =3D 16), the transfer will be rejected. This patch clamps max_chunk to the word size, preventing the transfer from being rejected. Signed-off-by: Yunhao Tian --- drivers/gpu/drm/drm_mipi_dbi.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c index 71b646c4131f..440dc9fec6cc 100644 --- a/drivers/gpu/drm/drm_mipi_dbi.c +++ b/drivers/gpu/drm/drm_mipi_dbi.c @@ -1182,6 +1182,15 @@ int mipi_dbi_spi_transfer(struct spi_device *spi, u3= 2 speed_hz, struct spi_message m; size_t chunk; int ret; + int w_size; + + if (bpw <=3D 8) + w_size =3D 1; + else if (bpw <=3D 16) + w_size =3D 2; + else + w_size =3D 4; + max_chunk -=3D (max_chunk % w_size); =20 spi_message_init_with_transfers(&m, &tr, 1); =20 --=20 2.25.1