From patchwork Tue Aug 25 09:05:39 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kishon Vijay Abraham I X-Patchwork-Id: 7069711 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D8FA19F305 for ; Tue, 25 Aug 2015 09:08:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 16D4A208B6 for ; Tue, 25 Aug 2015 09:08:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 18C61207EA for ; Tue, 25 Aug 2015 09:08:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932732AbbHYJGS (ORCPT ); Tue, 25 Aug 2015 05:06:18 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:53980 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932719AbbHYJGP (ORCPT ); Tue, 25 Aug 2015 05:06:15 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id t7P96BjW025053; Tue, 25 Aug 2015 04:06:11 -0500 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id t7P96B0J023916; Tue, 25 Aug 2015 04:06:11 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.224.2; Tue, 25 Aug 2015 04:06:11 -0500 Received: from a0393678ub.india.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id t7P95h4g031149; Tue, 25 Aug 2015 04:06:08 -0500 From: Kishon Vijay Abraham I To: , , , , , , CC: , Subject: [PATCH v2 08/11] mmc: host: omap_hsmmc: Workaround for errata id i802 Date: Tue, 25 Aug 2015 14:35:39 +0530 Message-ID: <1440493542-26150-9-git-send-email-kishon@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1440493542-26150-1-git-send-email-kishon@ti.com> References: <1440493542-26150-1-git-send-email-kishon@ti.com> MIME-Version: 1.0 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-8.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP According to errata i802, DCRC error interrupts (MMCHS_STAT[21] DCRC=0x1) can occur during the tuning procedure. The DCRC interrupt, occurs when the last tuning block fails (the last ratio tested). The delay from CRC check until the interrupt is asserted is bigger than the delay until assertion of the tuning end flag. Assertion of tuning end flag is what masks the interrupts. Because of this race, an erroneous DCRC interrupt occurs. The suggested workaround is to disable DCRC interrupts during the tuning procedure which is implemented here. Signed-off-by: Kishon Vijay Abraham I Signed-off-by: Sekhar Nori --- drivers/mmc/host/omap_hsmmc.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 43485c3..9ab0f6e 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -665,8 +665,17 @@ static void omap_hsmmc_enable_irq(struct omap_hsmmc_host *host, is_tuning = (cmd->opcode == MMC_SEND_TUNING_BLOCK) || (cmd->opcode == MMC_SEND_TUNING_BLOCK_HS200); - if (!is_tuning && host->use_dma) + if (is_tuning) { + /* + * OMAP5/DRA74X/DRA72x Errata i802: + * DCRC error interrupts (MMCHS_STAT[21] DCRC=0x1) can occur + * during the tuning procedure. So disable it during the + * tuning procedure. + */ + irq_mask &= ~DCRC_EN; + } else if (host->use_dma) { irq_mask &= ~(BRR_EN | BWR_EN); + } /* Disable timeout for erases */ if (cmd->opcode == MMC_ERASE)