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Subject: Re: [PATCH ] ipmi: kcs_bmc: fix IRQ exception if the channel is not
 open
To:     minyard@acm.org, arnd@arndb.de, gregkh@linuxfoundation.org,
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From:   "Wang, Haiyue" <haiyue.wang@linux.intel.com>
Message-ID: <3950b9ff-79d6-b0f8-91fb-1a13b34c24d2@linux.intel.com>
Date:   Sat, 23 Jun 2018 01:43:16 +0800
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On 2018-06-23 01:23, Wang, Haiyue wrote:
>> Maybe it's best to have the interrupt disabled unless the device is 
>> open.
>> You have to handle the interrupt disable race on a close, but with the
>> sync functions that shouldn't be too hard.
>>
> In fact, in BMC chip design, the LPC controller has many devices, such as
> Port 80 snoop, BT, KCS etc, they shares the same interrupt. :) 
BTW, for AST2500, if the BMC and PCH run under eSPI (like LPC) mode, and 
if we
disable the KCS devices, then reboot the BMC, it will cause the system 
hang, and
the KCS channel can't be used anymore. So we need always enable these 
used KCS
devices (keep the KCS enable register setting) for working well under 
eSPI mode.