From patchwork Fri Oct 18 15:35:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gregory CLEMENT X-Patchwork-Id: 11198751 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D0E87112B for ; Fri, 18 Oct 2019 15:35:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAE32222C3 for ; Fri, 18 Oct 2019 15:35:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389582AbfJRPfM (ORCPT ); Fri, 18 Oct 2019 11:35:12 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:50419 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726796AbfJRPfM (ORCPT ); Fri, 18 Oct 2019 11:35:12 -0400 Received: from localhost (aclermont-ferrand-651-1-259-53.w86-207.abo.wanadoo.fr [86.207.98.53]) (Authenticated sender: gregory.clement@bootlin.com) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 1CD74200005; Fri, 18 Oct 2019 15:35:10 +0000 (UTC) From: Gregory CLEMENT To: Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Nicolas Ferre , Alexandre Belloni , Ludovic Desroches , linux-arm-kernel@lists.infradead.org, Thomas Petazzoni , Mans Rullgard , Nicolas Ferre , Gregory CLEMENT Subject: [PATCH] spi: atmel: fix handling of cs_change set on non-last xfer Date: Fri, 18 Oct 2019 17:35:04 +0200 Message-Id: <20191018153504.4249-1-gregory.clement@bootlin.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org From: Mans Rullgard 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 --- Hello, This patch was first submitted 2 years[1] but was never applied while it has received the acked-by from Nicolas, and I don't see any review against it on the mailing list. So I resend it now. Thanks, Gregory [1]: https://lkml.org/lkml/2016/1/17/31 drivers/spi/spi-atmel.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index d88e2aa64839..9e84a93083bc 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -277,7 +277,6 @@ struct atmel_spi { bool use_pdc; bool keep_cs; - bool cs_active; u32 fifo_size; u8 native_cs_free; @@ -1416,11 +1415,9 @@ static int atmel_spi_one_transfer(struct spi_master *master, &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); } } @@ -1443,7 +1440,6 @@ static int atmel_spi_transfer_one_message(struct spi_master *master, atmel_spi_lock(as); cs_activate(as, spi); - as->cs_active = true; as->keep_cs = false; msg->status = 0;