[PATCH v2] phy: stm32-usphyc: add 200 to 300 us delay to fix timeout on some machines

[Michael Grzeschik]

Gentle Ping!

On Fri, Mar 10, 2023 at 11:44:38AM +0100, Michael Grzeschik wrote:
>Hi Fabrice,
>
>On Tue, Feb 28, 2023 at 06:28:21PM +0100, Fabrice Gasnier wrote:
>>On 2/27/23 16:13, Michael Grzeschik wrote:
>>>An minimum udelay of 200 us seems to be necessary on some machines. After
>>>the setup of the pll, which needs about 100 us to be locked there seem
>>>to be additional 100 us to get the phy really functional. Without this
>>>delay the usb runs not functional. With this additional short udelay
>>>this issue was not reported again.
>>>
>>>Signed-off-by: Michael Grzeschik <m.grzeschik at pengutronix.de>
>>>
>>
>>Hi Michael,
>>
>>Thank you for the updates,
>>
>>Fell free to add my:
>>Reviewed-by: Fabrice Gasnier <fabrice.gasnier at foss.st.com>
>
>Thanks!
>
>Through which tree will this be picked?
>Will it be possible to add this to v6.3?
>
>Regards,
>Michael
>
>>>---
>>>v1 -> v2: - changed the mdelay to udelay_range(200, 300), like suggested by fabrice
>>>          - moved the delay to pll enable so it will only be triggered once
>>>
>>> drivers/phy/st/phy-stm32-usbphyc.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>>
>>>diff --git a/drivers/phy/st/phy-stm32-usbphyc.c b/drivers/phy/st/phy-stm32-usbphyc.c
>>>index 5bb9647b078f12..dd469f57fba7eb 100644
>>>--- a/drivers/phy/st/phy-stm32-usbphyc.c
>>>+++ b/drivers/phy/st/phy-stm32-usbphyc.c
>>>@@ -317,6 +317,9 @@ static int stm32_usbphyc_pll_enable(struct stm32_usbphyc *usbphyc)
>>>
>>> 	stm32_usbphyc_set_bits(pll_reg, PLLEN);
>>>
>>>+	/* Wait for maximum lock time */
>>>+	usleep_range(200, 300);
>>>+
>>> 	return 0;
>>>
>>> reg_disable:
>>
>
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Pengutronix e.K.                           |                             |
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