linux-kernel - Re: [PATCH v1 2/2] usb: phy: Add USB3 PHY support for Intel LGM SoC

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Date:   Wed, 10 Jun 2020 09:06:40 +0800
From:   "Ramuthevar, Vadivel MuruganX" 
        <vadivel.muruganx.ramuthevar@...ux.intel.com>
To:     Philipp Zabel <p.zabel@...gutronix.de>,
        linux-kernel@...r.kernel.org, balbi@...nel.org
Cc:     gregkh@...uxfoundation.org, robh@...nel.org,
        devicetree@...r.kernel.org, linux-usb@...r.kernel.org,
        cheol.yong.kim@...el.com, qi-ming.wu@...el.com, yin1.li@...el.com,
        andriy.shevchenko@...el.com
Subject: Re: [PATCH v1 2/2] usb: phy: Add USB3 PHY support for Intel LGM SoC

Hi Philipp,

Thank you very much for review comments and your time...

On 9/6/2020 8:14 pm, Philipp Zabel wrote:
>> +
>> +	for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++) {
>> +		resets[i] = devm_reset_control_get(dev, CTL_RESETS[i]);
> Please use devm_reset_control_get_exclusive() instead.
Noted, will use it.
> 
>> +		if (IS_ERR(resets[i])) {
>> +			dev_err(dev, "%s reset not found\n", CTL_RESETS[i]);
>> +			return PTR_ERR(resets[i]);
>> +		}
>> +		reset_control_assert(resets[i]);
>> +	}
> You should request all reset controls first, and only then start
> asserting / deasserting, otherwise you may end up with partially
> asserted resets in case a later reset control is not found.
Agreed!, re-write the assert/de-assert logic as you have suggested.
> 
>> +
>> +	for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++) {
>> +		ta->resets[i] = devm_reset_control_get(dev, PHY_RESETS[i]);
> Same as above.
> 
>> +		if (IS_ERR(ta->resets[i])) {
>> +			dev_err(dev, "%s reset not found\n", PHY_RESETS[i]);
>> +			return PTR_ERR(ta->resets[i]);
>> +		}
>> +		reset_control_assert(ta->resets[i]);
>> +	}
>> +
>> +	for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++)
>> +		reset_control_deassert(resets[i]);
>> +	/* Need to wait at least 20us before de-assert the PHY */
>> +	usleep_range(20, 100);
> This waits 20us after de-asserting the reset, not before. Is this in the
> correct place?
yes, you are right, it's in wrong place, Thanks!

Regards
Vadivel
>