From patchwork Thu Apr 27 12:33:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joy Chakraborty X-Patchwork-Id: 13225451 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 88653C77B73 for ; Thu, 27 Apr 2023 12:34:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243371AbjD0MeE (ORCPT ); Thu, 27 Apr 2023 08:34:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243799AbjD0Mdz (ORCPT ); Thu, 27 Apr 2023 08:33:55 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7FED44B9 for ; Thu, 27 Apr 2023 05:33:44 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-b9a829a3de0so780490276.2 for ; Thu, 27 Apr 2023 05:33:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1682598824; x=1685190824; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=1ypFgisKdugG378RCE4wuNj0FpBiItt6cq8MGNIIYGA=; b=Otk4yIq6Sbhtb4TihxX60Psghxw0hddCiysw1B0c+w6rnLG6DP8tPh7lvgZ5M1w7Ye /KMpNEQS+6aA+ZZqtzogfKKjwXsEHaMZabvreo32p165z5+9THvfuz6i2eVem5FxByk5 NSkh1R4Dju3S2xWB3oOJfa8/VG+1AndSfU92fsztFbXNf2MW0nTgXYJmr5kbIEXH/KXe dJ0BL3lS/iY691UuIba82p7XuGmUI8tkKLjGMH9g/IvXuY1UdU9I/n3fQD07YYh+eS0J zYKWa0puQ3ZWy3qAXei/C3PLQsVTFyHGJdVqvOyMJIjn1Pv8ILZH8IMXqikGBxumAPgU fLqg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682598824; x=1685190824; 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=1ypFgisKdugG378RCE4wuNj0FpBiItt6cq8MGNIIYGA=; b=Z/xVOjfVShIrJ+TKJoL+STCdUI6A96ArIvtqio6ckMlpYmwp0KCPaS6SqwP2FVRhkU +PsEwOR8nhmSzKxadme7d2stW+gxAJ0z54Lzqspp9BZwvqVWvHlbNFFGeGGGiT/xK/wg BZjXcXL3on/xlTAoQ0hszF+exXmqAA3PNV4m6uAeY1j+HK8wQqjEfutizuphqCQddkTT 8pkGxKOcbvJCXg8hW4XbCn2+UIB70yUac35DJ9l7+w5dCkuId3ftYO31na/UNpSCzD2U n2DF1uWFxn0P1XMk9yP4/ZN59zu3sLX2fSsGKzaDCStR1SLtKA6o4fL972hNQDsq2/SC jrhA== X-Gm-Message-State: AC+VfDzMyC5PN27YoU5cAc3mmqX+r+8pmyNr0BenQBXhTdHyAymOZMDI ccYBZguyEKVpkMwcA4ZtBgIKSgrj6QOMxA== X-Google-Smtp-Source: ACHHUZ7HFF9cztNmd7ivBvM2Tt5Ka4hMiw6tetPGvOkizaiT3+YmYw1mFqCq61cGJ0i8nIVRQdvUFhcK28i9rA== X-Received: from joychakr.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:6ea]) (user=joychakr job=sendgmr) by 2002:a05:6902:188d:b0:b96:a18:1b4c with SMTP id cj13-20020a056902188d00b00b960a181b4cmr497926ybb.13.1682598824170; Thu, 27 Apr 2023 05:33:44 -0700 (PDT) Date: Thu, 27 Apr 2023 12:33:14 +0000 In-Reply-To: <20230427123314.1997152-1-joychakr@google.com> Mime-Version: 1.0 References: <20230427123314.1997152-1-joychakr@google.com> X-Mailer: git-send-email 2.40.1.495.gc816e09b53d-goog Message-ID: <20230427123314.1997152-6-joychakr@google.com> Subject: [PATCH v9 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 Reviewed-by: Serge Semin Tested-by: Serge Semin * tested on Baikal-T1 based system with DW SPI-looped back interface transferring a chunk of data with DFS:8,12,16. --- drivers/spi/spi-dw-core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c index c3bfb6c84cab..4976e3b8923e 100644 --- a/drivers/spi/spi-dw-core.c +++ b/drivers/spi/spi-dw-core.c @@ -426,7 +426,10 @@ 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;