From 3fcb027d7fd749569665d34a79ce2a8e00bc2ed6 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Thu, 1 Apr 2010 10:03:25 +0200 Subject: ARM: MXC: mxcmmc: work around a bug in the SDHC busy line handling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MX3 SoCs have a silicon bug which corrupts CRC calculation of multi-block transfers when connected SDIO peripheral doesn't drive the BUSY line as required by the specs. One way to prevent this is to only allow 1-bit transfers. Another way is playing tricks with the DMA engine, but this isn't mainline yet. So for now, we live with the performance drawback of 1-bit transfers until a nicer solution is found. This patch introduces a new host controller callback 'init_card' which is for now only called from mmc_sdio_init_card(). Signed-off-by: Daniel Mack Cc: Sascha Hauer Cc: Dan Williams Cc: Volker Ernst Cc: Jiri Kosina Cc: Michał Mirosław Signed-off-by: Sascha Hauer --- drivers/mmc/core/sdio.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/mmc/core') diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index 2dd4cfe7ca17..b9dee28ee7d0 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -295,6 +295,12 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr, card->type = MMC_TYPE_SDIO; + /* + * Call the optional HC's init_card function to handle quirks. + */ + if (host->ops->init_card) + host->ops->init_card(host, card); + /* * For native busses: set card RCA and quit open drain mode. */ -- cgit v1.2.3