From 8a7013f47196abed7e6a40e93d1de1639cd46228 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 10 Jul 2015 17:03:03 +0200 Subject: [PATCH] mmc: sunxi: Don't start commands while the card is busy Some sdio wifi modules have not been working reliable with the sunxi-mmc host code. This turns out to be caused by it starting new commands while the card signals that it is still busy processing a previous command. This commit fixes this, thereby fixing the wifi reliability issues on the Cubietruck and other sunxi boards using sdio wifi. Reported-by: Eugene K Suggested-by: Eugene K Cc: Eugene K Cc: Arend van Spriel Signed-off-by: Hans de Goede --- Changes in v2: -Properly accredit Eugene K for coming up with the fix for this --- drivers/mmc/host/sunxi-mmc.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) --- a/drivers/mmc/host/sunxi-mmc.c +++ b/drivers/mmc/host/sunxi-mmc.c @@ -289,6 +289,24 @@ static int sunxi_mmc_init_host(struct mm return 0; } +/* Wait for card to report ready before starting a new cmd */ +static int sunxi_mmc_wait_card_ready(struct sunxi_mmc_host *host) +{ + unsigned long expire = jiffies + msecs_to_jiffies(500); + u32 rval; + + do { + rval = mmc_readl(host, REG_STAS); + } while (time_before(jiffies, expire) && (rval & SDXC_CARD_DATA_BUSY)); + + if (rval & SDXC_CARD_DATA_BUSY) { + dev_err(mmc_dev(host->mmc), "Error R1 ready timeout\n"); + return -EIO; + } + + return 0; +} + static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host, struct mmc_data *data) { @@ -383,6 +401,8 @@ static void sunxi_mmc_send_manual_stop(s u32 arg, cmd_val, ri; unsigned long expire = jiffies + msecs_to_jiffies(1000); + sunxi_mmc_wait_card_ready(host); + cmd_val = SDXC_START | SDXC_RESP_EXPIRE | SDXC_STOP_ABORT_CMD | SDXC_CHECK_RESPONSE_CRC; @@ -597,6 +617,11 @@ static int sunxi_mmc_oclk_onoff(struct s { unsigned long expire = jiffies + msecs_to_jiffies(250); u32 rval; + int ret; + + ret = sunxi_mmc_wait_card_ready(host); + if (ret) + return ret; rval = mmc_readl(host, REG_CLKCR); rval &= ~(SDXC_CARD_CLOCK_ON | SDXC_LOW_POWER_ON); @@ -784,6 +809,13 @@ static void sunxi_mmc_request(struct mmc mmc_request_done(mmc, mrq); return; } + + ret = sunxi_mmc_wait_card_ready(host); + if (ret) { + mrq->cmd->error = ret; + mmc_request_done(mmc, mrq); + return; + } if (data) { ret = sunxi_mmc_map_dma(host, data);