From: Guan Yung Tseng <guan.yung.tseng@ni.com>
To: <gregkh@linuxfoundation.org>, <hch@infradead.org>
Cc: <linux-serial@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
"Guan Yung Tseng" <guan.yung.tseng@ni.com>
Subject: [PATCH v2] 8250_pci.c: Update NI specific devices class to multi serial
Date: Tue, 22 Jan 2019 17:19:42 +0800 [thread overview]
Message-ID: <1548148782-3414-1-git-send-email-guan.yung.tseng@ni.com> (raw)
On, Jan 14, 2019 at 10:10:05PM +0800, Guan Yung Tseng wrote:
>> Modified NI devices class to PCI_CLASS_COMMUNICATION_MULTISERIAL.
>> The reason of doing this is because all NI multi port serial cards
>> use PCI_CLASS_COMMUNICATION_OTHER class and thus fail the
>> serial_pci_is_class_communication test added in the commit 7d8905d06405
>> ("serial: 8250_pci: Enable device after we check black list").
>>
>> Signed-off-by: Guan Yung Tseng <guan.yung.tseng@ni.com>
>> ---
>> drivers/tty/serial/8250/8250_pci.c | 20 ++++++++++++++++++++
>> 1 file changed, 20 insertions(+)
>>
>> diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
>> index 4986b4a..0949db1 100644
>> --- a/drivers/tty/serial/8250/8250_pci.c
>> +++ b/drivers/tty/serial/8250/8250_pci.c
>> @@ -663,6 +663,13 @@ static int pci_xircom_init(struct pci_dev *dev)
>> return 0;
>> }
>>
>> +static int pci_ni_probe(struct pci_dev *dev)
>> +{
>> + dev->class = PCI_CLASS_COMMUNICATION_MULTISERIAL << 8 |
>> + (dev->class & 0xff);
>
> As Christoph said, this looks really odd. This field comes from the
> PCI structure on the device, it should not be modified by the kernel.
>
> Unless the device is broken and needs to be fixed up in the kernel?
>
> Also, you have sent 2 different patches here for this type of issue, are
> both needed? If so, please resend both of them as a patch series, with
> more explainations in this one as to why you are modifying this field.
>
> I've dropped all pending patches from you from my queue now.
>
Hi Christoph and Greg,
Sorry for the confusion sending 2 different patches to solve the same
issue. I should have wait for your response before sending antoher
patch to solve the similar issue.
For some historical reason, NI serial devices use
PCI_CLASS_COMMUNICATION_OTHER class code. Yes, I understand that
the class code should read from config space instead modified from
kernel. But these devices are shipped to the market for many years.
That's why I am trying to fix the problem in the kernel.
I will send another simple patch again to fix the problem.
next reply other threads:[~2019-01-22 9:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-22 9:19 Guan Yung Tseng [this message]
-- strict thread matches above, loose matches on Subject: below --
2019-01-15 10:10 [PATCH v2] 8250_pci.c: Update NI specific devices class to multi serial Guan Yung Tseng
2019-01-15 13:31 ` Christoph Hellwig
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