From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751617AbWFUO05 (ORCPT ); Wed, 21 Jun 2006 10:26:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751602AbWFUO0j (ORCPT ); Wed, 21 Jun 2006 10:26:39 -0400 Received: from 85.8.24.16.se.wasadata.net ([85.8.24.16]:61856 "EHLO mail.drzeus.cx") by vger.kernel.org with ESMTP id S1751599AbWFUO0I (ORCPT ); Wed, 21 Jun 2006 10:26:08 -0400 From: Pierre Ossman Subject: [PATCH 10/21] [MMC] Avoid sdhci DMA boundaries Date: Wed, 21 Jun 2006 16:26:08 +0200 Cc: Pierre Ossman To: rmk+lkml@arm.linux.org.uk Cc: linux-kernel@vger.kernel.org Message-Id: <20060621142608.8857.96591.stgit@poseidon.drzeus.cx> In-Reply-To: <20060621142323.8857.69197.stgit@poseidon.drzeus.cx> References: <20060621142323.8857.69197.stgit@poseidon.drzeus.cx> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org The sdhci controllers will issue an interrupt when a configurable number of bytes have been transfered using DMA. The purpose is to handle multiple, scattered memory pages. Unfortunately, it requires that all transfers are completely aligned to memory pages, which we cannot guarantee. So we just disable the function. Signed-off-by: Pierre Ossman --- drivers/mmc/sdhci.c | 13 +++++++++---- drivers/mmc/sdhci.h | 1 + 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c index eb6aee4..57200e4 100644 --- a/drivers/mmc/sdhci.c +++ b/drivers/mmc/sdhci.c @@ -326,6 +326,9 @@ static void sdhci_prepare_data(struct sd DBG("tsac %d ms nsac %d clk\n", data->timeout_ns / 1000000, data->timeout_clks); + /* Sanity checks */ + BUG_ON((1 << data->blksz_bits) * data->blocks > 524288); + /* timeout in us */ target_timeout = data->timeout_ns / 1000 + data->timeout_clks / host->clock; @@ -375,7 +378,9 @@ static void sdhci_prepare_data(struct sd host->remain = host->cur_sg->length; } - writew(1 << data->blksz_bits, host->ioaddr + SDHCI_BLOCK_SIZE); + /* We do not handle DMA boundaries, so set it to max (512 KiB) */ + writew(SDHCI_MAKE_BLKSZ(7, 1 << data->blksz_bits), + host->ioaddr + SDHCI_BLOCK_SIZE); writew(data->blocks, host->ioaddr + SDHCI_BLOCK_COUNT); } @@ -1188,10 +1193,10 @@ static int __devinit sdhci_probe_slot(st mmc->max_phys_segs = 16; /* - * Maximum number of sectors in one transfer. Limited by sector - * count register. + * Maximum number of sectors in one transfer. Limited by DMA boundary + * size (512KiB), which means (512 KiB/512=) 1024 entries. */ - mmc->max_sectors = 0x3FFF; + mmc->max_sectors = 1024; /* * Maximum segment size. Could be one segment with the maximum number diff --git a/drivers/mmc/sdhci.h b/drivers/mmc/sdhci.h index f8df28f..8ed2a89 100644 --- a/drivers/mmc/sdhci.h +++ b/drivers/mmc/sdhci.h @@ -23,6 +23,7 @@ #define PCI_SLOT_INFO_FIRST_BAR_MASK 0x #define SDHCI_DMA_ADDRESS 0x00 #define SDHCI_BLOCK_SIZE 0x04 +#define SDHCI_MAKE_BLKSZ(dma, blksz) (((dma & 0x7) << 12) | (blksz & 0xFFF)) #define SDHCI_BLOCK_COUNT 0x06