[PATCH] spi: imx: mx51-ecspi: Fix CONFIGREG delay comment

[PATCH] spi: imx: mx51-ecspi: Fix CONFIGREG delay comment

[Marek Vasut]

For (2 * 1000000) / min_speed_hz < 10 to be true in naturals with zero,
the min_speed_hz must above 222222. Update the comment. No functional
change.

Fixes: 6fd8b8503a0dc ("spi: spi-imx: Fix out-of-order CS/SCLK operation at low speeds")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Mark Brown <broonie@kernel.org>
---
Note: Drop the Fixes if it makes no sense to backport this.
---
 drivers/spi/spi-imx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index cb9f7261c4385..f474f76753bc1 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -593,7 +593,7 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
 	}
 
 	delay = (2 * 1000000) / min_speed_hz;
-	if (likely(delay < 10))	/* SCLK is faster than 100 kHz */
+	if (likely(delay < 10))	/* SCLK is faster than 222.2 kHz */
 		udelay(delay);
 	else			/* SCLK is _very_ slow */
 		usleep_range(delay, delay + 10);
-- 
2.30.2

Re: [PATCH] spi: imx: mx51-ecspi: Fix CONFIGREG delay comment

[Mark Brown]

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On Mon, Jul 26, 2021 at 12:15:02PM +0200, Marek Vasut wrote:
> For (2 * 1000000) / min_speed_hz < 10 to be true in naturals with zero,
> the min_speed_hz must above 222222. Update the comment. No functional
> change.

This doesn't apply against current code, please check and resend.

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Re: [PATCH] spi: imx: mx51-ecspi: Fix CONFIGREG delay comment

[Uwe Kleine-König]

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On Mon, Jul 26, 2021 at 12:15:02PM +0200, Marek Vasut wrote:
> For (2 * 1000000) / min_speed_hz < 10 to be true in naturals with zero,
> the min_speed_hz must above 222222. Update the comment. No functional
> change.

With integer division delay is < 10 if min_speed_hz >= 200001.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH] spi: imx: mx51-ecspi: Fix CONFIGREG delay comment

[Marek Vasut]

On 7/27/21 3:01 PM, Uwe Kleine-König wrote:
> On Mon, Jul 26, 2021 at 12:15:02PM +0200, Marek Vasut wrote:
>> For (2 * 1000000) / min_speed_hz < 10 to be true in naturals with zero,
>> the min_speed_hz must above 222222. Update the comment. No functional
>> change.
> 
> With integer division delay is < 10 if min_speed_hz >= 200001.

Right, it's not 181, 100 or 222. I'll send a V2 and clarify this.

Re: [PATCH] spi: imx: mx51-ecspi: Fix CONFIGREG delay comment

[Marek Vasut]

On 7/27/21 2:15 PM, Mark Brown wrote:
> On Mon, Jul 26, 2021 at 12:15:02PM +0200, Marek Vasut wrote:
>> For (2 * 1000000) / min_speed_hz < 10 to be true in naturals with zero,
>> the min_speed_hz must above 222222. Update the comment. No functional
>> change.
> 
> This doesn't apply against current code, please check and resend.

Hm, yes, it conflicts with
[PATCH V2] spi: imx: mx51-ecspi: Fix low-speed CONFIGREG delay calculation

So maybe I'll wait until this one gets applied and picked by stable, and 
then I'll send the comment fix ? That should make things easier.

Re: [PATCH] spi: imx: mx51-ecspi: Fix CONFIGREG delay comment

[Mark Brown]

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On Tue, Jul 27, 2021 at 05:55:26PM +0200, Marek Vasut wrote:

> So maybe I'll wait until this one gets applied and picked by stable, and
> then I'll send the comment fix ? That should make things easier.

Sure.  No need to wait for stable I guess, once it's applied everything
should be fine.

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Re: [PATCH] spi: imx: mx51-ecspi: Fix CONFIGREG delay comment

[Mark Brown]

On Mon, 26 Jul 2021 12:15:02 +0200, Marek Vasut wrote:
> For (2 * 1000000) / min_speed_hz < 10 to be true in naturals with zero,
> the min_speed_hz must above 222222. Update the comment. No functional
> change.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: imx: mx51-ecspi: Fix CONFIGREG delay comment
      commit: 36c2530ea963884eeb0097169f853fdc36f16ad7

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark