Most registers need to wait until the command is completed, not necessarily until the bus is free. At least, R-Car 2+ SoCs can signal that via the CBSY bit, so let's use it there instead of SCLKDIVEN to save a little bit of delay.
Signed-off-by: Wolfram Sang <[email protected]> --- Tested with a Renesas Lager board (H2). Moved big files around across different SD cards, re- inserted cards multiple times. All worked fine. @Dirk: can you do some additional testing for your use case? That would be much appreciated! Changes since RFC (from Jan 2016): * rebased to latest code base * use existing bit defines instead of creating new ones drivers/mmc/host/renesas_sdhi_core.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c index 82150a96639195..288153b5f6835e 100644 --- a/drivers/mmc/host/renesas_sdhi_core.c +++ b/drivers/mmc/host/renesas_sdhi_core.c @@ -395,12 +395,14 @@ static void renesas_sdhi_hw_reset(struct tmio_mmc_host *host) sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL)); } -static int renesas_sdhi_wait_idle(struct tmio_mmc_host *host) +static int renesas_sdhi_wait_idle(struct tmio_mmc_host *host, u32 bit) { int timeout = 1000; + /* CBSY is set when busy, SCLKDIVEN is cleared when busy */ + u32 wait_state = (bit == TMIO_STAT_CMD_BUSY ? TMIO_STAT_CMD_BUSY : 0); - while (--timeout && !(sd_ctrl_read16_and_16_as_32(host, CTL_STATUS) - & TMIO_STAT_SCLKDIVEN)) + while (--timeout && (sd_ctrl_read16_and_16_as_32(host, CTL_STATUS) + & bit) == wait_state) udelay(1); if (!timeout) { @@ -413,18 +415,23 @@ static int renesas_sdhi_wait_idle(struct tmio_mmc_host *host) static int renesas_sdhi_write16_hook(struct tmio_mmc_host *host, int addr) { + u32 bit = TMIO_STAT_SCLKDIVEN; + switch (addr) { case CTL_SD_CMD: case CTL_STOP_INTERNAL_ACTION: case CTL_XFER_BLK_COUNT: - case CTL_SD_CARD_CLK_CTL: case CTL_SD_XFER_LEN: case CTL_SD_MEM_CARD_OPT: case CTL_TRANSACTION_CTL: case CTL_DMA_ENABLE: case EXT_ACC: - return renesas_sdhi_wait_idle(host); + if (host->pdata->flags & TMIO_MMC_MIN_RCAR2) + bit = TMIO_STAT_CMD_BUSY; + /* fallthrough */ + case CTL_SD_CARD_CLK_CTL: + return renesas_sdhi_wait_idle(host, bit); } return 0; -- 2.11.0
