Current DWMMC driver used to give FIFO underrun/overrun error every 3rd time for mmc rescan command. In current code FIFO_DEPTH is getting calculated after reading the default FIFOTH register and extracting the RX_WMARK bits from it i.e (RX_WMARK = FIFO_DEPTH/2 -1). Instead of storing the correct value, we were recalculating the FIFO_DEPT each time which is not correct.
Based on "[PATCH V9 3/9] DWMMC: Initialise dwmci and resolve EMMC read write issues" http://permalink.gmane.org/gmane.comp.boot-loaders.u-boot/160247
Signed-off-by: Hatim Ali hatim.rv@samsung.com Signed-off-by: Rajeshwari Shinde rajeshwari.s@samsung.com --- Changes in V2: - remove fifoth_val local variable - Rebased on top of "[PATCH V9 3/9] DWMMC: Initialise dwmci and resolve EMMC read write issues". drivers/mmc/dw_mmc.c | 14 ++++++-------- 1 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c index 1307b12..5da20ed 100644 --- a/drivers/mmc/dw_mmc.c +++ b/drivers/mmc/dw_mmc.c @@ -312,7 +312,7 @@ static void dwmci_set_ios(struct mmc *mmc) static int dwmci_init(struct mmc *mmc) { struct dwmci_host *host = (struct dwmci_host *)mmc->priv; - u32 fifo_size, fifoth_val; + u32 fifo_size;
dwmci_writel(host, DWMCI_PWREN, 1);
@@ -332,15 +332,13 @@ static int dwmci_init(struct mmc *mmc) dwmci_writel(host, DWMCI_IDINTEN, 0); dwmci_writel(host, DWMCI_BMOD, 1);
- fifo_size = dwmci_readl(host, DWMCI_FIFOTH); - fifo_size = ((fifo_size & RX_WMARK_MASK) >> RX_WMARK_SHIFT) + 1; - if (host->fifoth_val) { - fifoth_val = host->fifoth_val; - } else { - fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size / 2 - 1) | + if (!host->fifoth_val) { + fifo_size = dwmci_readl(host, DWMCI_FIFOTH); + fifo_size = ((fifo_size & RX_WMARK_MASK) >> RX_WMARK_SHIFT) + 1; + host->fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size / 2 - 1) | TX_WMARK(fifo_size / 2); } - dwmci_writel(host, DWMCI_FIFOTH, fifoth_val); + dwmci_writel(host, DWMCI_FIFOTH, host->fifoth_val);
dwmci_writel(host, DWMCI_CLKENA, 0); dwmci_writel(host, DWMCI_CLKSRC, 0);