Messages in this thread | | | From | Lukasz Stelmach <> | Subject | Re: [PATCH v2 7/9] spi: spi-s3c64xx: Ensure cur_speed holds actual clock value | Date | Mon, 24 Aug 2020 15:17:03 +0200 |
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It was <2020-08-22 sob 14:43>, when Krzysztof Kozlowski wrote: > On Fri, Aug 21, 2020 at 06:13:59PM +0200, Łukasz Stelmach wrote: >> cur_speed is used to calculate transfer timeout and needs to be >> set to the actual value of (half) the clock speed for precise >> calculations. > > If you need this only for timeout calculation just divide it in > s3c64xx_wait_for_dma().
I divide it here to keep the relationship between the value the variable holds and the one that is inside clk_* (See? It's multiplied 3 lines above). If you look around every single clk_get_rate() call in the file is divided by two.
> Otherwise why only if (cmu) case is updated?
You are righ I will update that too.
However, I wonder if it is even possible that the value read from S3C64XX_SPI_CLK_CFG would be different than the one written to it?
> You are also affecting here not only timeout but > s3c64xx_enable_datapath() which is not mentioned in commit log. In other > words, this looks wrong.
Indeed, there is a reference too. I've corrected the message.
>> >> Cc: Tomasz Figa <tfiga@chromium.org> >> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com> >> --- >> drivers/spi/spi-s3c64xx.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c >> index 02de734b8ab1..89c162efe355 100644 >> --- a/drivers/spi/spi-s3c64xx.c >> +++ b/drivers/spi/spi-s3c64xx.c >> @@ -626,6 +626,7 @@ static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) >> ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * 2); >> if (ret) >> return ret; >> + sdd->cur_speed = clk_get_rate(sdd->src_clk) / 2; >> } else { >> /* Configure Clock */ >> val = readl(regs + S3C64XX_SPI_CLK_CFG); >> -- >> 2.26.2 >> > >
-- Łukasz Stelmach Samsung R&D Institute Poland Samsung Electronics [unhandled content-type:application/pgp-signature] | |