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Subject: Re: [PATCH] USB:ehci:fix ehci hardware problem
To:     <gregkh@linuxfoundation.org>, <mathias.nyman@intel.com>,
        <stern@rowland.harvard.edu>, <liudongdong3@huawei.com>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <kong.kongxinwei@hisilicon.com>, <yisen.zhuang@huawei.com>
References: <1617865425-28782-1-git-send-email-liulongfang@huawei.com>
From:   liulongfang <liulongfang@huawei.com>
Message-ID: <177a1fbd-b6f0-2e67-2e5a-5b05d2015b3a@huawei.com>
Date:   Thu, 8 Apr 2021 15:19:55 +0800
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On 2021/4/8 15:03, Longfang Liu wrote:
> When rebooting the EHCI driver, ehci_shutdown() will be called.
> if the sbrn flag is 0, ehci_shutdown() will return directly.
> 
> Our EHCI hardware does not define the SBRN register, which cause
> its value to default to 0. The sbrn flag being 0 will cause the
> EHCI interrupt signal to not be turned off after reboot. An interrupt
> that is not closed will cause an exception to the device sharing
> the interrupt.
> 
> Currently, our hardware has this problem. We hope to solve this
> problem by skipping reading the sbrn register value. On the next
> generation of hardware, we will define this SBRN register in accordance
> with the controller standard.
> 
> Signed-off-by: Longfang Liu <liulongfang@huawei.com>
> ---
>  drivers/usb/host/ehci-pci.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
> index 3c3820a..5dc6821 100644
> --- a/drivers/usb/host/ehci-pci.c
> +++ b/drivers/usb/host/ehci-pci.c
> @@ -291,6 +291,8 @@ static int ehci_pci_setup(struct usb_hcd *hcd)
>  	if (pdev->vendor == PCI_VENDOR_ID_STMICRO
>  	    && pdev->device == PCI_DEVICE_ID_STMICRO_USB_HOST)
>  		;	/* ConneXT has no sbrn register */
> +	else if (pdev->vendor == PCI_VENDOR_ID_HUAWEI)
> +		;	/* sbrn register is undefined */
>  	else
>  		pci_read_config_byte(pdev, 0x60, &ehci->sbrn);
>  
> 
Sorry, please ignore this patch, I will resend it.
Thanks.
Longfang.