From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754021Ab3GIXUl (ORCPT ); Tue, 9 Jul 2013 19:20:41 -0400 Received: from mail-qc0-f202.google.com ([209.85.216.202]:40540 "EHLO mail-qc0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753557Ab3GIXTa (ORCPT ); Tue, 9 Jul 2013 19:19:30 -0400 From: Doug Anderson To: Chris Ball Cc: Olof Johansson , Jaehoon Chung , Seungwon Jeon , James Hogan , Grant Grundler , Alim Akhtar , Abhilash Kesavan , Tomasz Figa , Doug Anderson , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 4/5] mmc: dw_mmc: Always setup the bus after suspend/resume Date: Tue, 9 Jul 2013 16:19:20 -0700 Message-Id: <1373411961-23812-5-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.8.3 In-Reply-To: <1373411961-23812-1-git-send-email-dianders@chromium.org> References: <1373391071-6312-1-git-send-email-dianders@chromium.org> <1373411961-23812-1-git-send-email-dianders@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org After suspend/resume all of the dw_mmc registers are reset to defaults. We restore most of them, but specifically don't setup the clock registers after resume unless we've got a powered card. Things still work because the core will eventually call set_ios() and we'll set things up. There doesn't seem to be any reason that I can see _not_ to set things up after resume. Restoring this state makes the code easier to reason about and should help prevent bugs. It also allows us to do a register dump before and after suspend/resume to confirm that we've set things up OK. I examined the state of the dw_mmc instance before and after suspend after this patch. I had no card inserted in an SD card slot. Before this patch, differences were: * CLKDIV (0x08) * CLKENA (0x10) * TMOUT (0x14) * CMD (0x2C) - difference is not important * CLKSEL (0x9C - exynos specific) After this patch, only TMOUT was different. I have a separate patch for that. Signed-off-by: Doug Anderson --- Changes in v2: None drivers/mmc/host/dw_mmc.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 7a5ce6a..be095b7 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -2499,9 +2499,7 @@ int dw_mci_resume(struct dw_mci *host) struct dw_mci_slot *slot = host->slot[i]; if (!slot) continue; - if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) { - dw_mci_set_ios(slot->mmc, &slot->mmc->ios); - } + dw_mci_set_ios(slot->mmc, &slot->mmc->ios); ret = mmc_resume_host(host->slot[i]->mmc); if (ret < 0) -- 1.8.3