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In-Reply-To: <039c9214-423f-0f62-f6d2-6f2c969512fa@kontron.de>
From:   Fabio Estevam <festevam@gmail.com>
Date:   Mon, 20 Sep 2021 17:50:45 -0300
Message-ID: <CAOMZO5A4x_v8wtGyDjLdMg_hS1=UZH3LV-e+Dyz=spmSaLyAaw@mail.gmail.com>
Subject: Re: imx8mm board crash in drivers/usb/chipidea/ci_hdrc_imx.c
To:     Frieder Schrempf <frieder.schrempf@kontron.de>
Cc:     Heiko Thiery <heiko.thiery@gmail.com>,
        Peter Chen <peter.chen@nxp.com>, Jun Li <jun.li@nxp.com>,
        Yu Kuai <yukuai3@huawei.com>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Mark Brown <broonie@kernel.org>,
        USB list <linux-usb@vger.kernel.org>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Shawn Guo <shawnguo@kernel.org>
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Hi Frieder,

On Mon, Sep 20, 2021 at 11:26 AM Frieder Schrempf
<frieder.schrempf@kontron.de> wrote:

> Commit ed5a419bb019 ("usb: chipidea: imx: "fsl,usbphy" phandle is not
> mandatory now") explains, that the core driver already covers reading
> the "phys" property (see ci_hdrc_probe()):
>
>   Since the chipidea common code support get the USB PHY phandle from
>   "phys", the glue layer is not mandatory to get the "fsl,usbphy"
>   phandle any more.
>
> This seems to be the reason why ci_hdrc_imx_probe() doesn't return any
> error in case "fsl,usbphy" is not set. It expects that the core will
> handle data->phy = NULL and already checks for a "phys" property.

chipidea core populates ci->usb_phy when phys is used.

The charger detection function only checks data->usb_phy, so they
don't see ci->usb_phy that was populated by the chipidea core.

We could change the signature of all charger detection functions to
receive struct ci_hdrc *ci, but that will be a huge patch that will
probably not meet
the stable requirements, so I think to minimally fix stable we should
go with the proposed fix I suggested.


>
> Therefore I'm not sure Fabio's fix is the right way to go. Could it be
> that the ci_hdrc_imx driver expects that it will be probed before the
> ci_hdrc core and this isn't true in Heiko's case?