diff options
| -rw-r--r-- | drivers/mmc/host/sdhci.c | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index c83d11080da0..0f1a8876e3b1 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1151,6 +1151,7 @@ void sdhci_set_clock(struct sdhci_host *host, unsigned int clock) int real_div = div, clk_mul = 1; u16 clk = 0; unsigned long timeout; + bool switch_base_clk = false; host->mmc->actual_clock = 0; @@ -1188,15 +1189,25 @@ void sdhci_set_clock(struct sdhci_host *host, unsigned int clock) <= clock) break; } - /* - * Set Programmable Clock Mode in the Clock - * Control register. - */ - clk = SDHCI_PROG_CLOCK_MODE; - real_div = div; - clk_mul = host->clk_mul; - div--; - } else { + if ((host->max_clk * host->clk_mul / div) <= clock) { + /* + * Set Programmable Clock Mode in the Clock + * Control register. + */ + clk = SDHCI_PROG_CLOCK_MODE; + real_div = div; + clk_mul = host->clk_mul; + div--; + } else { + /* + * Divisor can be too small to reach clock + * speed requirement. Then use the base clock. + */ + switch_base_clk = true; + } + } + + if (!host->clk_mul || switch_base_clk) { /* Version 3.00 divisors must be a multiple of 2. */ if (host->max_clk <= clock) div = 1; |