Re: [PATCH 08/10] usb: chipidea: host: calibrate the PHY after starting the host

From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
To: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>,
	Bartosz Golaszewski <brgl@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Linus Walleij <linusw@kernel.org>, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Xu Yang <xu.yang_2@nxp.com>, Peng Fan <peng.fan@nxp.com>,
	Vinod Koul <vkoul@kernel.org>,
	Neil Armstrong <neil.armstrong@linaro.org>,
	Peter Chen <peter.chen@kernel.org>,
	Pavankumar Kondeti <quic_pkondeti@quicinc.com>,
	Stephen Boyd <stephen.boyd@linaro.org>,
	Konrad Dybcio <konradybcio@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>,
	linux-arm-msm@vger.kernel.org, linux-gpio@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-usb@vger.kernel.org, linux-phy@lists.infradead.org,
	Greg Kroah-Hartman <gregkh@suse.de>,
	Peter Chen <peter.chen@nxp.com>
Subject: Re: [PATCH 08/10] usb: chipidea: host: calibrate the PHY after starting the host
Date: Tue, 18 Aug 2026 12:09:25 +0200	[thread overview]
Message-ID: <66f8e084-9bc2-412d-b617-70baf0f9f4cd@oss.qualcomm.com> (raw)
In-Reply-To: <20260810-msm8974-usb-hsic-v1-8-e5f93ea76ffa@oss.qualcomm.com>

On 8/10/26 5:42 PM, Dmitry Baryshkov wrote:
> Some PHYs need a final programming step after the host controller is
> up: the Qualcomm HSIC PHY latches the device connect at the moment
> HSIC mode is engaged, so that write must happen with the root port
> already running, or an already-connected HSIC device (the strobe/data
> lines have no hotplug) is never seen. The generic PHY framework
> provides phy_calibrate() for exactly this kind of post-init fixup and
> dwc3 already calls it; the chipidea host does not, leaving no place
> for such PHY work.
> 
> Call phy_calibrate() once the HCD has been added, next to the existing
> i.MX HSIC active-event hook which serves the same purpose. PHYs
> without a calibrate op are unaffected.
> 
> Assisted-by: Claude:claude-fable-5
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> ---

PHY APIs happily eat nullptrs fwiw

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad

>  drivers/usb/chipidea/host.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
> index ced6076a8248..62bb2999edb6 100644
> --- a/drivers/usb/chipidea/host.c
> +++ b/drivers/usb/chipidea/host.c
> @@ -15,6 +15,7 @@
>  #include <linux/regulator/consumer.h>
>  #include <linux/string_choices.h>
>  #include <linux/pinctrl/consumer.h>
> +#include <linux/phy/phy.h>
>  
>  #include "../host/ehci.h"
>  
> @@ -192,6 +193,9 @@ static int host_start(struct ci_hdrc *ci)
>  			(ci->platdata->flags & CI_HDRC_IMX_IS_HSIC))
>  			ci->platdata->notify_event
>  				(ci, CI_HDRC_IMX_HSIC_ACTIVE_EVENT);
> +
> +		if (ci->phy)
> +			phy_calibrate(ci->phy);
>  	}
>  
>  	return ret;
> 

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