Re: [PATCH v2 7/9] spi: spi-s3c64xx: Ensure cur_speed holds actual clock value
From: Krzysztof Kozlowski <krzk@kernel.org>
Date: 2020-08-22 12:43:33
Also in:
linux-samsung-soc, linux-spi, lkml
Possibly related (same subject, not in this thread)
- 2020-08-25 · Re: [PATCH v2 7/9] spi: spi-s3c64xx: Ensure cur_speed holds actual clock value · Lukasz Stelmach <l.stelmach@samsung.com>
- 2020-08-25 · Re: [PATCH v2 7/9] spi: spi-s3c64xx: Ensure cur_speed holds actual clock value · Tomasz Figa <tfiga@chromium.org>
- 2020-08-25 · Re: [PATCH v2 7/9] spi: spi-s3c64xx: Ensure cur_speed holds actual clock value · Lukasz Stelmach <l.stelmach@samsung.com>
- 2020-08-24 · Re: [PATCH v2 7/9] spi: spi-s3c64xx: Ensure cur_speed holds actual clock value · Tomasz Figa <tfiga@chromium.org>
- 2020-08-24 · Re: [PATCH v2 7/9] spi: spi-s3c64xx: Ensure cur_speed holds actual clock value · Lukasz Stelmach <l.stelmach@samsung.com>
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(). Otherwise why only if (cmu) case is updated? 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. Best regards, Krzysztof
quoted hunk ↗ jump to hunk
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
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