| Message ID | 20160906191652.01a11698@vm (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 3aef463222eaf1ca505629e93a0b64e4040a4472 |
| Headers | show |
On Tue, Sep 06, 2016 at 07:16:52PM +0200, Matthias Seidel wrote:
> Avoid ending up with a higher frequency than requested
I'm missing patch 1/2 here?
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index c85e4b3..27960e4 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -300,7 +300,7 @@ static int dw_spi_transfer_one(struct spi_master *master, if (transfer->speed_hz != dws->current_freq) { if (transfer->speed_hz != chip->speed_hz) { /* clk_div doesn't support odd number */ - chip->clk_div = (dws->max_freq / transfer->speed_hz + 1) & 0xfffe; + chip->clk_div = (DIV_ROUND_UP(dws->max_freq, transfer->speed_hz) + 1) & 0xfffe; chip->speed_hz = transfer->speed_hz; } dws->current_freq = transfer->speed_hz;
Avoid ending up with a higher frequency than requested Signed-off-by: Matthias Seidel <kernel@mseidel.net> --- Previously failing example: requested transfer freq: 16MHz max_freq = 200MHz calculated clk_div = 12 actual frequency = 200/12 = 16.6666MHz v3: I wasn't aware of this macro, better readability. --- drivers/spi/spi-dw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)