Re: [PATCH 0/3 v2] i2c: i801: enable irq

[Daniel Kurtz]

On Fri, Jan 6, 2012 at 7:35 PM, Jean Delvare <khali@xxxxxxxxxxxx> wrote:
> Hi Daniel,
>
> On Fri,  6 Jan 2012 18:58:19 +0800, Daniel Kurtz wrote:
>> This is a second version of a set of patches enables the Intel PCH SMBus
>> controller interrupt.  It refactors the second two patches a little bit by
>> relying on DEV_ERR interrupt for timeouts, instead of using an explicit
>> wait_event_timeout.
>>
>> The first attempt received absolutely no response. Maybe this time someone
>> will be interested.
>
> I was on vacation. But I am very interested and will review and test
> your patches. There have been several attempts to add IRQ support to
> i2c-i801 in the past but each time there was a blocker issue which
> prevented it from making it into mainline. Hopefully this time we'll
> get it there!
>
>>
>> The SMBus Host Controller Interrupt can signify:
>>  INTR - the end of a complete transaction
>>  DEV_ERR - that a device did not ACK a transaction
>>  BYTE_DONE - the completion of a single byte during a byte-by-byte transaction
>>
>> This patchset arrives with the following caveats:
>>
>>  1)  It has only been tested with a Cougar Point (Intel 6 Series PCH) SMBus
>> controller, so the irq is only enabled for that chip type.
>
> I can test on ICH10 easily, and also on ICH7 and ICH3-M if needed.
>
>>  2) It has not been tested with any devices that do transactions that use the
>>     PEC.  In fact, I believe that an additional small patch would be required
>>     to the driver working correctly in interrupt mode with PEC.
>>
>>  3) It has not been tested in SMBus Slave mode.
>>
>>  4) It has not been tested with SMI#-type interrupts.
>>
>>  5) The BIOS has to configure the PCH SMBus IRQ properly.
>>
>>  6) It has not been tested with a device that does byte-by-byte smbus (non-i2c)
>>     reads.
>
> I think I can test this.
>
>>  7) It has not been tested with smbus 'process call' transactions.
>
> But not this.
>
>> If would be very helpful if somebody could help test on other chipsets, with
>> a PEC device, or on additional BIOS that woudl be very helpful.
>
> I will do what I can with the hardware I have here.

Jean,
Ping?


>
>> In the meantime, the interrupt behavior is only enabled on the Cougar Point,
>> and even here, it can be completely disabled with the "Interrupt" feature like
>> other advanced features of the driver.
>>
>> Daniel Kurtz (3):
>>   i2c: i801: refactor i801_block_transaction_byte_by_byte
>>   i2c: i801: enable irq for i801 smbus transactions
>>   i2c: i801: enable irq for byte_by_byte transactions
>>
>>  drivers/i2c/busses/i2c-i801.c |  199 ++++++++++++++++++++++++++++++++++++-----
>>  1 files changed, 175 insertions(+), 24 deletions(-)
>
> --
> Jean Delvare
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