Hi Philip, Chris, On 5-10-2010 10:34, Chris Ball wrote: > Hi David, > > On Thu, Sep 30, 2010 at 08:03:14PM -0700, Philip Rakity wrote: >> From: Philip Rakity <[email protected]> >> Date: Thu, 30 Sep 2010 15:34:24 -0700 >> Subject: [PATCH] sdhci: adjust sd 3.0 host controller spec clock divider >> >> The sd 3.0 host spec does not require the clock divider to be a power of 2.
The text and code for sd 3.0 was talking about a multiple of 2, not a power of 2 >> Signed-off-by: Philip Rakity <[email protected]> >> --- >> drivers/mmc/host/sdhci.c | 8 +++----- >> 1 files changed, 3 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >> index 96c7f60..73a94fe 100644 >> --- a/drivers/mmc/host/sdhci.c >> +++ b/drivers/mmc/host/sdhci.c >> @@ -1003,14 +1003,12 @@ static void sdhci_set_clock(struct sdhci_host *host, >> unsigned int clock) >> goto out; >> >> if (host->version >= SDHCI_SPEC_300) { >> - /* Version 3.00 divisors must be a multiple of 2. */ >> if (host->max_clk <= clock) >> div = 1; >> else { >> - for (div = 2; div < SDHCI_MAX_DIV_SPEC_300; div += 2) { >> - if ((host->max_clk / div) <= clock) >> - break; >> - } >> + div = host->max_clk/clock; >> + if (host->max_clk % clock) >> + div++; If you mean to divide and round up, wouldn't : + div = DIV_ROUND_UP (host->max_clk, clock); be nicer and cheaper? Can SDHCI_MAX_DIV_SPEC_300 be dropped safely? (don't have access to the sd 3.0 specs neither) Hein -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
