From nobody Wed Feb 11 13:39:16 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 D7370C77B75 for ; Tue, 9 May 2023 08:23:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235098AbjEIIXx (ORCPT ); Tue, 9 May 2023 04:23:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229615AbjEIIX1 (ORCPT ); Tue, 9 May 2023 04:23:27 -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 7F85CD2EF for ; Tue, 9 May 2023 01:23:14 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-559ea6b1065so96637187b3.0 for ; Tue, 09 May 2023 01:23:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683620593; x=1686212593; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=EOqtouxRu25HRRsWlk2RLw7lnYbQ6zK+okIr8VJZgWs=; b=DzKDPmMEpZHjb9GuaKoRNMsHWMhtL9oVCv0krVFeDx3758tICEhyUNkOrse8cAKqLS 3phGAD7as5/VjeDKqJAc7r8JScHrf9QIQ7hPFdfbPNXYOcxXP/tbUqeP3SroM2IMIQ+j W3MS7WdHxLXxKFyWDF7s5buuMqpLjryFJIERteQbjNtAyssZK7P30HxanRG2FtHfj6rA irmKx5af8Dixewafm4ngw2zEVpyeTMGddd7k7xTzTRfboRUySqZXbhhyODBkVUyijzMc l5+Gxi2eM95Vv29rd/EqJ3jOzqxQKIyVcEV+qDRUEkRS0El5b6Nov5RxWB6vh9eA3pVy RDzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683620593; x=1686212593; 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=EOqtouxRu25HRRsWlk2RLw7lnYbQ6zK+okIr8VJZgWs=; b=ESSHKKhtmNTCX1ghdHNsPu96P4g4lDhvQxt5IpQgycs7e65WsfVl8FksjMazltx6Qz Q/BgWqRA8LBpf/ldDPQllkDsuFbqmFSNV95vaceMym8GOEHoT76EQe9tJHmCYZ2UnzWB MX0eNKvcv8rizThjEzycsjXJgBOLRyiUigZvU70Z41v1lFpUL2cwf8Vrqukx3r/SIicf dD/HaNC5AB2sJRvPczrllO1X9rirNEfX9jfBdUOV+XLDuUd+2PNfKimkqfHjmLbK4kHB 5/iB2RASpaj6ET+Cluk/m0T9CJLy4/Wf0Euq47g+84U6a+VTwSJaPZQwZLFZ6hKbQ6N1 2Fhw== X-Gm-Message-State: AC+VfDyPDxWzF8yuWULkgT5JUcuQr8xaupH96+FxfepQr2vdS07zx6Qg 61mHCFFVuy6AqLeZHWS1ZF8gwf1oHmqgSQ== X-Google-Smtp-Source: ACHHUZ4XbHXAlK/d1ZXHVHpmbaQP/hWvDOZbsJII83AzL84Im5dgEZyeWJYq2SKh58+6rINiLiFE2xjNvOqoSA== X-Received: from joychakr.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:6ea]) (user=joychakr job=sendgmr) by 2002:a81:af0e:0:b0:55a:5641:54be with SMTP id n14-20020a81af0e000000b0055a564154bemr8245389ywh.6.1683620593763; Tue, 09 May 2023 01:23:13 -0700 (PDT) Date: Tue, 9 May 2023 08:22:44 +0000 In-Reply-To: <20230509082244.1069623-1-joychakr@google.com> Mime-Version: 1.0 References: <20230509082244.1069623-1-joychakr@google.com> X-Mailer: git-send-email 2.40.1.521.gf1e218fcd8-goog Message-ID: <20230509082244.1069623-6-joychakr@google.com> Subject: [PATCH v10 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 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; =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 2.40.1.521.gf1e218fcd8-goog