Re: [PATCH v2] phy: stm32-usphyc: add 200 to 300 us delay to fix timeout on some machines
From: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Date: 2023-02-28 17:29:43
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linux-phy
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 <redacted>
Hi Michael, Thank you for the updates, Fell free to add my: Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com> Best Regards, Fabrice
quoted hunk ↗ jump to hunk
--- 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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