diff options
| author | Heiko Stuebner <heiko@sntech.de> | 2018-09-21 10:59:45 +0200 |
|---|---|---|
| committer | Philipp Tomsich <philipp.tomsich@theobroma-systems.com> | 2018-10-02 09:35:09 +0200 |
| commit | 05fa06b9606387ad4a65723d93a83b36a98d600b (patch) | |
| tree | 47003edf45f9519a4d6026b51f5c45290a33f19a /drivers/mmc | |
| parent | 2ba8bf207481cfb319f54a1bef67f6f068831a58 (diff) | |
mmc: dw_mmc: check fifo status with a timeout in fifo mode
While trying to enable the dw_mmc on rk3188 I managed to confuse
and hang the dw_mmc controller into not delivering further data.
The fifo state never became ready and the driver was iterating in
the while loop reading 0-byte packets forever.
So inspired by how other implementations handle this, check the fifo-
state beforhand and add a timeout to catch any glaring fifo issues
without hanging uboot altogether.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/dw_mmc.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c index 13180fc0d6..3c702b3ed8 100644 --- a/drivers/mmc/dw_mmc.c +++ b/drivers/mmc/dw_mmc.c @@ -92,6 +92,24 @@ static void dwmci_prepare_data(struct dwmci_host *host, dwmci_writel(host, DWMCI_BYTCNT, data->blocksize * data->blocks); } +static int dwmci_fifo_ready(struct dwmci_host *host, u32 bit, u32 *len) +{ + u32 timeout = 20000; + + *len = dwmci_readl(host, DWMCI_STATUS); + while (--timeout && (*len & bit)) { + udelay(200); + *len = dwmci_readl(host, DWMCI_STATUS); + } + + if (!timeout) { + debug("%s: FIFO underflow timeout\n", __func__); + return -ETIMEDOUT; + } + + return 0; +} + static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data) { int ret = 0; @@ -122,7 +140,12 @@ static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data) if (data->flags == MMC_DATA_READ && (mask & DWMCI_INTMSK_RXDR)) { while (size) { - len = dwmci_readl(host, DWMCI_STATUS); + ret = dwmci_fifo_ready(host, + DWMCI_FIFO_EMPTY, + &len); + if (ret < 0) + break; + len = (len >> DWMCI_FIFO_SHIFT) & DWMCI_FIFO_MASK; len = min(size, len); @@ -136,7 +159,12 @@ static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data) } else if (data->flags == MMC_DATA_WRITE && (mask & DWMCI_INTMSK_TXDR)) { while (size) { - len = dwmci_readl(host, DWMCI_STATUS); + ret = dwmci_fifo_ready(host, + DWMCI_FIFO_FULL, + &len); + if (ret < 0) + break; + len = fifo_depth - ((len >> DWMCI_FIFO_SHIFT) & DWMCI_FIFO_MASK); |