From: Alan Stern <stern@rowland.harvard.edu>
To: Vincent Shih <vincent.sunplus@gmail.com>
Cc: gregkh@linuxfoundation.org, p.zabel@pengutronix.de,
davem@davemloft.net, vladimir.oltean@nxp.com,
linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
devicetree@vger.kernel.org, wells.lu@sunplus.com
Subject: Re: [PATCH v4 1/2] usb: host: ehci-sunplus: Add driver for ehci in Sunplus SP7021
Date: Fri, 29 Apr 2022 11:37:32 -0400 [thread overview]
Message-ID: <YmwGPDNXNfx2RqLY@rowland.harvard.edu> (raw)
In-Reply-To: <1651220876-26705-2-git-send-email-vincent.sunplus@gmail.com>
On Fri, Apr 29, 2022 at 04:27:55PM +0800, Vincent Shih wrote:
> Add driver for ehci in Sunplus SP7021
>
> Signed-off-by: Vincent Shih <vincent.sunplus@gmail.com>
> ---
> Changes in v4:
> - Implement power_on, power_off and power_suspend functions.
Did you test these? Did you try to rmmod the ehci-sunplus module after
adding these functions?
> diff --git a/drivers/usb/host/ehci-sunplus.c b/drivers/usb/host/ehci-sunplus.c
> new file mode 100644
> index 0000000..4d8e20d
> --- /dev/null
> +++ b/drivers/usb/host/ehci-sunplus.c
> @@ -0,0 +1,289 @@
...
> +static void sp_ehci_platform_power_off(struct platform_device *pdev)
> +{
> + struct usb_hcd *hcd = platform_get_drvdata(pdev);
> + struct sp_ehci_priv *sp_priv = hcd_to_sp_ehci_priv(hcd);
> +
> + phy_power_off(sp_priv->phy);
> + phy_exit(sp_priv->phy);
Notice that this dereferences a field contained in the sp_ehci_priv
extension to the usb_hcd structure.
...
> +static int ehci_sunplus_remove(struct platform_device *pdev)
> +{
> + struct usb_hcd *hcd = platform_get_drvdata(pdev);
> + struct usb_ehci_pdata *pdata = pdev->dev.platform_data;
> +
> + usb_remove_hcd(hcd);
> + usb_put_hcd(hcd);
This call deallocates the usb_hcd structure.
> +
> + if (pdata->power_off)
> + pdata->power_off(pdev);
But here you dereference a field that it contains. This power-off
operation must occur _before_ the usb_put_hcd() call.
Alan Stern
next prev parent reply other threads:[~2022-04-29 15:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-29 8:27 [PATCH v4 0/2] Add driver for EHCI in Sunplus SP7021 Vincent Shih
2022-04-29 8:27 ` [PATCH v4 1/2] usb: host: ehci-sunplus: Add driver for ehci " Vincent Shih
2022-04-29 12:07 ` Philipp Zabel
2022-04-29 15:37 ` Alan Stern [this message]
2022-04-30 1:26 ` Alan Stern
2022-04-29 8:27 ` [PATCH v4 2/2] dt-bindings: usb: Add bindings doc for Sunplus EHCI driver Vincent Shih
2022-04-29 20:53 ` Krzysztof Kozlowski
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