From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4AC5C352A1 for ; Sat, 8 Feb 2020 18:38:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB2562253D for ; Sat, 8 Feb 2020 18:38:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728515AbgBHSiS (ORCPT ); Sat, 8 Feb 2020 13:38:18 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33692 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727682AbgBHS3g (ORCPT ); Sat, 8 Feb 2020 13:29:36 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1j0UrF-0003cT-Qz; Sat, 08 Feb 2020 18:29:33 +0000 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1j0UrE-000CKn-S1; Sat, 08 Feb 2020 18:29:32 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Mark Brown" , "Nicolas Ferre" , "Mans Rullgard" , "Gregory CLEMENT" Date: Sat, 08 Feb 2020 18:19:29 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 030/148] spi: atmel: fix handling of cs_change set on non-last xfer In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.82-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mans Rullgard commit fed8d8c7a6dc2a76d7764842853d81c770b0788e upstream. The driver does the wrong thing when cs_change is set on a non-last xfer in a message. When cs_change is set, the driver deactivates the CS and leaves it off until a later xfer again has cs_change set whereas it should be briefly toggling CS off and on again. This patch brings the behaviour of the driver back in line with the documentation and common sense. The delay of 10 us is the same as is used by the default spi_transfer_one_message() function in spi.c. [gregory: rebased on for-5.5 from spi tree] Fixes: 8090d6d1a415 ("spi: atmel: Refactor spi-atmel to use SPI framework queue") Signed-off-by: Mans Rullgard Acked-by: Nicolas Ferre Signed-off-by: Gregory CLEMENT Link: https://lore.kernel.org/r/20191018153504.4249-1-gregory.clement@bootlin.com Signed-off-by: Mark Brown [bwhh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- drivers/spi/spi-atmel.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -242,7 +242,6 @@ struct atmel_spi { struct atmel_spi_dma dma; bool keep_cs; - bool cs_active; }; /* Controller-specific per-slave state */ @@ -1190,11 +1189,9 @@ static int atmel_spi_one_transfer(struct &msg->transfers)) { as->keep_cs = true; } else { - as->cs_active = !as->cs_active; - if (as->cs_active) - cs_activate(as, msg->spi); - else - cs_deactivate(as, msg->spi); + cs_deactivate(as, msg->spi); + udelay(10); + cs_activate(as, msg->spi); } } @@ -1217,7 +1214,6 @@ static int atmel_spi_transfer_one_messag atmel_spi_lock(as); cs_activate(as, spi); - as->cs_active = true; as->keep_cs = false; msg->status = 0;