From nobody Wed Dec 17 20:59:24 2025 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 5C7EAC77B71 for ; Tue, 18 Apr 2023 05:29:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230385AbjDRF3u (ORCPT ); Tue, 18 Apr 2023 01:29:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229662AbjDRF3p (ORCPT ); Tue, 18 Apr 2023 01:29:45 -0400 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C44465A4 for ; Mon, 17 Apr 2023 22:29:31 -0700 (PDT) Received: by mail-pj1-x104a.google.com with SMTP id 98e67ed59e1d1-24763adb145so713532a91.2 for ; Mon, 17 Apr 2023 22:29:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1681795771; x=1684387771; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Fmf17OkL5SCBMBWD99k+zYNzeo76qcWOQzqTUdEaNA4=; b=ZLGNlq1PGDuNXmKXCLEpwmCrcSVfz8bJTIn49O4DCgqv4BhkDZPhhsZZqXBoVChY4+ Ra4LogSmWM4SDLlCF7CSa4DPJ5nSCBspbm82HDOGzaGkTlGaNSBT0E1ZSB7aNab3llYn Ix7lWThLXLkhH0eOr+JohXRTjVQUdlA++00RQl2KVy784t6G/WBvEmUXA7+NnFt8AP18 xCt2KWflMpoZkec7CqL5XH/aZXVICoNiD+ymyHfhXbGnazme9J1wWTxmpnZLXlF7GlMy QsJ7TbF3vu4Y9erMH8vv+2tqX9teQG0ilKR6CUhtZFSnnEYffZj5ANb6hn7OBDEqBP7x ZTtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681795771; x=1684387771; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Fmf17OkL5SCBMBWD99k+zYNzeo76qcWOQzqTUdEaNA4=; b=C8/MHgCb50LU/oy3KZo7aGe0UqFXTUUDV1QN9bAtpX8F5CtI3KI5urKq2OuVHysoC9 HyMDH0jxRrmQM8BJ5CkYltIy8Jwo+u9oNzlm52I0BnesXPkFQChjK2srRU/FDQq5S5xv vSxy8i/lBITikLOO96ftCnMCtd9tFyykwvfYQaEd46VbmobUymnyQzTDRLnJdGl/q/Wn wmkkblrVJq/CJmq17WE5IqtlxAUBB2hrQ2UdJkbxji6zVkVR8aY6eOvtw32e8qLYtzg8 TB4XNYy+sq1skluxLV2CYKzWpOpMda4gF3nYjfte8bOySkuAudfoocQBDQYZQiR9kg8L AdtQ== X-Gm-Message-State: AAQBX9c9wDWFhgcFKPTTYTr+R067e7njJAXSMxpvrH4zvYNfEWbhHkNh f7ZqMy7hDBqM+eQ3sCxWsXzR+5duCJVCOQ== X-Google-Smtp-Source: AKy350aajvAgsYG7NiI4EKXnrMPoSQwdFAFDCxuRpR+k/AvuEzgKLZO54jV/kPal++hSl5YcIVmP4pdBx8AHtw== X-Received: from joychakr.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:6ea]) (user=joychakr job=sendgmr) by 2002:a17:90a:2b07:b0:240:c13d:1325 with SMTP id x7-20020a17090a2b0700b00240c13d1325mr280814pjc.5.1681795771097; Mon, 17 Apr 2023 22:29:31 -0700 (PDT) Date: Tue, 18 Apr 2023 05:29:02 +0000 In-Reply-To: <20230418052902.1336866-1-joychakr@google.com> Mime-Version: 1.0 References: <20230418052902.1336866-1-joychakr@google.com> X-Mailer: git-send-email 2.40.0.634.g4ca3ef3211-goog Message-ID: <20230418052902.1336866-6-joychakr@google.com> Subject: [PATCH v7 5/5] spi: dw: Round of n_bytes to power of 2 From: Joy Chakraborty To: Serge Semin , Mark Brown , Andy Shevchenko Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, manugautam@google.com, rohitner@google.com, Joy Chakraborty Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" n_bytes variable in the driver represents the number of bytes per word that needs to be sent/copied to fifo. Bits/word can be between 8 and 32 bits from the client but in memory they are a power of 2, same is mentioned in spi.h header: " * @bits_per_word: Data transfers involve one or more words; word sizes * like eight or 12 bits are common. In-memory wordsizes are * powers of two bytes (e.g. 20 bit samples use 32 bits). * This may be changed by the device's driver, or left at the * default (0) indicating protocol words are eight bit bytes. * The spi_transfer.bits_per_word can override this for each transfer. " Hence, round of n_bytes to a power of 2 to avoid values like 3 which would generate unalligned/odd accesses to memory/fifo. Fixes: a51acc2400d4 ("spi: dw: Add support for 32-bits max xfer size") Suggested-by: Andy Shevchenko Signed-off-by: Joy Chakraborty --- drivers/spi/spi-dw-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c index c3bfb6c84cab..a6486db46c61 100644 --- a/drivers/spi/spi-dw-core.c +++ b/drivers/spi/spi-dw-core.c @@ -426,7 +426,7 @@ static int dw_spi_transfer_one(struct spi_controller *m= aster, int ret; =20 dws->dma_mapped =3D 0; - dws->n_bytes =3D DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE); + dws->n_bytes =3D roundup_pow_of_two(DIV_ROUND_UP(transfer->bits_per_word,= BITS_PER_BYTE)); dws->tx =3D (void *)transfer->tx_buf; dws->tx_len =3D transfer->len / dws->n_bytes; dws->rx =3D transfer->rx_buf; --=20 2.40.0.634.g4ca3ef3211-goog