From: James Hogan Date: Wed, 29 Jun 2011 08:30:47 +0000 (+0100) Subject: mmc: dw_mmc: reset FIFO after an error X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=94dd5b3371c989b32685a00a54cba7bb530f864d;p=mv-sheeva.git mmc: dw_mmc: reset FIFO after an error If an error occurs mid way through a transaction (such as a missing CRC status response after the 2nd block written out of 3), then the FIFO may still contain data which will interfere with the next transaction. Therefore after an error has been detected, reset the fifo using the CTRL register. Signed-off-by: James Hogan Acked-by: Will Newton Tested-by: Jaehoon Chung Signed-off-by: Chris Ball --- diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 0dac397f37f..0c839d3338d 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -849,7 +849,7 @@ static void dw_mci_tasklet_func(unsigned long priv) struct mmc_command *cmd; enum dw_mci_state state; enum dw_mci_state prev_state; - u32 status; + u32 status, ctrl; spin_lock(&host->lock); @@ -929,6 +929,16 @@ static void dw_mci_tasklet_func(unsigned long priv) status); data->error = -EIO; } + /* + * After an error, there may be data lingering + * in the FIFO, so reset it - doing so + * generates a block interrupt, hence setting + * the scatter-gather pointer to NULL. + */ + host->sg = NULL; + ctrl = mci_readl(host, CTRL); + ctrl |= SDMMC_CTRL_FIFO_RESET; + mci_writel(host, CTRL, ctrl); } else { data->bytes_xfered = data->blocks * data->blksz; data->error = 0;