Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753792Ab1FXNKh (ORCPT ); Fri, 24 Jun 2011 09:10:37 -0400 Received: from multi.imgtec.com ([194.200.65.239]:2886 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752161Ab1FXNKf (ORCPT ); Fri, 24 Jun 2011 09:10:35 -0400 Message-ID: <4E0488EE.5040706@imgtec.com> Date: Fri, 24 Jun 2011 13:54:06 +0100 From: James Hogan User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.15) Gecko/20101027 Fedora/3.0.10-1.fc12 Thunderbird/3.0.10 MIME-Version: 1.0 To: James Hogan CC: Chris Ball , Will Newton , Jaehoon Chung , Kyungmin Park , Matt Fleming , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, james@albanarts.com Subject: [PATCH 1/6] mmc: dw_mmc: clear TXDR/RXDR ints before enabling References: <4E0488A9.6050109@imgtec.com> In-Reply-To: <4E0488A9.6050109@imgtec.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 24 Jun 2011 12:54:07.0445 (UTC) FILETIME=[CDEAE850:01CC326D] X-SEF-Processed: 7_3_0_01158__2011_06_24_13_54_10 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2092 Lines: 55 DMA is only used for transactions exceeding a certain length, otherwise PIO is used. The TXDR and RXDR interrupts are masked when in DMA mode but still fire. When switching to PIO mode (e.g. to get SCR field when an SD card is inserted) these interrupts are not cleared and so they trigger the ISR as soon as they are unmasked. If the previous DMA did a write, then the ISR will handle the TXDR interrupt even if the transaction is a read, completing the transaction without modifying the read buffer. This is fixed primarily by clearing these two interrupts before unmasking them when setting up PIO mode, and also by making the ISR more robust by only handling TXDR/RXDR in the correct read/write direction. Signed-off-by: James Hogan --- drivers/mmc/host/dw_mmc.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 22be372..08c0592 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -497,6 +497,7 @@ static void dw_mci_submit_data(struct dw_mci *host, struct mmc_data *data) else host->dir_status = DW_MCI_SEND_STATUS; + mci_writel(host, RINTSTS, SDMMC_INT_TXDR | SDMMC_INT_RXDR); temp = mci_readl(host, INTMASK); temp |= SDMMC_INT_TXDR | SDMMC_INT_RXDR; mci_writel(host, INTMASK, temp); @@ -1230,13 +1231,13 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id) if (pending & SDMMC_INT_RXDR) { mci_writel(host, RINTSTS, SDMMC_INT_RXDR); - if (host->sg) + if (host->dir_status == DW_MCI_RECV_STATUS && host->sg) dw_mci_read_data_pio(host); } if (pending & SDMMC_INT_TXDR) { mci_writel(host, RINTSTS, SDMMC_INT_TXDR); - if (host->sg) + if (host->dir_status == DW_MCI_SEND_STATUS && host->sg) dw_mci_write_data_pio(host); } -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/