From patchwork Fri Apr 14 12:05:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joy Chakraborty X-Patchwork-Id: 13211383 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 799F1C77B6E for ; Fri, 14 Apr 2023 12:06:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230351AbjDNMGQ (ORCPT ); Fri, 14 Apr 2023 08:06:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230296AbjDNMGN (ORCPT ); Fri, 14 Apr 2023 08:06:13 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F24F6AD27 for ; Fri, 14 Apr 2023 05:05:49 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-54c17fb245dso239897117b3.21 for ; Fri, 14 Apr 2023 05:05:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1681473949; x=1684065949; 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=BjBk4IFfphPEvkF6oNu0FALs6uDTF7SOGFv3xTJX9fN+uejADR6Jzn/lNLnIuNHVaS 7rK0a+DvjrxnYz2Nc6HcVasynWLHhIY2+xJw9uGOOQYkxclfiVPQrYrB/7tyIMsM04j0 tt/ToVH+x2LAv0Zk66w7fjuo571bhxyaYUbq4r3r0No8bHmqgiZz0sTryCw7bvu85vKX WIF4wo+llgaXEzmoubYyqe5rHKGjcJ7q3xmHdwAyoWE7mITNRmDV990wb4UToHE6vdJB 7nNI62LjTFqAyebdPa+uMh8n7u5b7PWA+50T1QrAiKnlYZctziaSErhec27QXUPE+JXD iK9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681473949; x=1684065949; 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=I1c9KWdI90sTojMjxJ+TKOByJ9RIavD75AR/jaQCw1JSTCxQ/SdF2QNsyZgccEuNN2 WKDwx+QwgiWMw6gYg+aqNifamv5YMDzwXJncg47GiD46uiAUuRsU50wCfe2VhXBu8YQ7 vrbu4HcjbVO/hlqHky4SjkwgYwrILP4E/4CxPGWmiSzs4g2Aduf/N9L5yY8aCjrjbzbl KGbt9GUcMnDer6qbVFHwakuVdCqe4war58H2b6+Ngo9P95h9USpk9riP5Er+beN2By3v yVy6xz0nC5IbcX3vU+2MHLmLDI/xCJR5WTgxNSRb1eBC/wnlZKa5YGwi6cCYzOetMC0R oeHg== X-Gm-Message-State: AAQBX9ecGCp/0IwOFaEnR2J1tYGvlF5MsVLwBHzlBDcIIgJco9NkRBiV ZX4vCuZxsqIWL0pGhmMcu4pvk2poufyOFw== X-Google-Smtp-Source: AKy350btW+p1AMej9BMNQTOwi1zlSSgujlz7EFCFmu5Ck4LJ+KBKvqkoAjGiLKh42cRQVIydYBvZfMzF9ULK4A== X-Received: from joychakr.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:6ea]) (user=joychakr job=sendgmr) by 2002:a25:ca83:0:b0:b8f:6944:afeb with SMTP id a125-20020a25ca83000000b00b8f6944afebmr1727314ybg.3.1681473948816; Fri, 14 Apr 2023 05:05:48 -0700 (PDT) Date: Fri, 14 Apr 2023 12:05:20 +0000 In-Reply-To: <20230414120520.360291-1-joychakr@google.com> Mime-Version: 1.0 References: <20230414120520.360291-1-joychakr@google.com> X-Mailer: git-send-email 2.40.0.634.g4ca3ef3211-goog Message-ID: <20230414120520.360291-6-joychakr@google.com> Subject: [PATCH v6 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-spi@vger.kernel.org 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 *master, int ret; dws->dma_mapped = 0; - dws->n_bytes = DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE); + dws->n_bytes = roundup_pow_of_two(DIV_ROUND_UP(transfer->bits_per_word, BITS_PER_BYTE)); dws->tx = (void *)transfer->tx_buf; dws->tx_len = transfer->len / dws->n_bytes; dws->rx = transfer->rx_buf;