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Date:   Tue, 15 Feb 2022 07:02:57 +0100
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Subject: Re: [PATCH] tty: serial: 8250: add missing pci_dev_put() before
 return
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From:   Jiri Slaby <jirislaby@kernel.org>
To:     Qing Wang <wangqing@vivo.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
References: <1644890454-65258-1-git-send-email-wangqing@vivo.com>
 <67ace5d3-02b3-034d-969f-9a05bbdd8e30@kernel.org>
In-Reply-To: <67ace5d3-02b3-034d-969f-9a05bbdd8e30@kernel.org>
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On 15. 02. 22, 6:55, Jiri Slaby wrote:
> On 15. 02. 22, 3:00, Qing Wang wrote:
>> From: Wang Qing <wangqing@vivo.com>
>>
>> pci_get_slot() increases its reference count, the caller must
>> decrement the reference count by calling pci_dev_put()
>>
>> Signed-off-by: Wang Qing <wangqing@vivo.com>
>> ---
>>   drivers/tty/serial/8250/8250_lpss.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/tty/serial/8250/8250_lpss.c 
>> b/drivers/tty/serial/8250/8250_lpss.c
>> index d3bafec..57e462f
>> --- a/drivers/tty/serial/8250/8250_lpss.c
>> +++ b/drivers/tty/serial/8250/8250_lpss.c
>> @@ -149,6 +149,8 @@ static int byt_serial_setup(struct lpss8250 *lpss, 
>> struct uart_port *port)
>>       /* Disable TX counter interrupts */
>>       writel(BYT_TX_OVF_INT_MASK, port->membase + BYT_TX_OVF_INT);
>> +    pci_dev_put(dma_dev);
> 
> 
> What about the "return -ENODEV" few lines above?

On the top of that, the code stores the pointer to the dev:
param->dma_dev = &dma_dev->dev;

So we should likely put the device in ->exit(), not ->setup().

thanks,
-- 
js
suse labs