The current code dealing with calculating mmc->f_min is a bit complicated. Additionally, the attempt to set an initial clock rate should explicitly use a rate between 100KHz to 400 KHz, according the (e)MMC/SD specs, which it doesn't. Fix the problem and clean up the code by using clk_round_rate() to pick the nearest minimum rate to 100KHz. Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> --- Note, this is compile tested only so I hope someone with the HW can give it a go. --- drivers/mmc/host/meson-gx-mmc.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index 5eca88b..c672e01 100644 --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -240,7 +240,6 @@ static int meson_mmc_clk_init(struct meson_host *host) const char *mux_parent_names[MUX_CLK_NUM_PARENTS]; unsigned int mux_parent_count = 0; const char *clk_div_parents[1]; - unsigned int f_min = UINT_MAX; u32 clk_reg, cfg; /* get the mux parents */ @@ -257,20 +256,10 @@ static int meson_mmc_clk_init(struct meson_host *host) return ret; } - host->mux_parent_rate[i] = clk_get_rate(host->mux_parent[i]); mux_parent_names[i] = __clk_get_name(host->mux_parent[i]); mux_parent_count++; - if (host->mux_parent_rate[i] < f_min) - f_min = host->mux_parent_rate[i]; } - /* cacluate f_min based on input clocks, and max divider value */ - if (f_min != UINT_MAX) - f_min = DIV_ROUND_UP(CLK_SRC_XTAL_RATE, CLK_DIV_MAX); - else - f_min = 4000000; /* default min: 400 MHz */ - host->mmc->f_min = f_min; - /* create the mux */ snprintf(clk_name, sizeof(clk_name), "%s#mux", dev_name(host->dev)); init.name = clk_name; @@ -325,9 +314,13 @@ static int meson_mmc_clk_init(struct meson_host *host) writel(cfg, host->regs + SD_EMMC_CFG); ret = clk_prepare_enable(host->cfg_div_clk); - if (!ret) - ret = meson_mmc_clk_set(host, f_min); + if (ret) + return ret; + + /* Get the nearest minimum clock to 100KHz */ + host->mmc->f_min = clk_round_rate(host->cfg_div_clk, 100000); + ret = meson_mmc_clk_set(host, host->mmc->f_min); if (!ret) clk_disable_unprepare(host->cfg_div_clk); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
