Re: Intel ICHx bus driver

[Felix Rubinstein <felixru-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Hi Jean/i2c guys,

I'm having hard time to send straight I2C transaction of arbitrary length.
I use i2c_smbus_write_i2c_block_data(fd, buf[0], datac - 1, &buf[1]);
from user-space to send the aforementioned transaction, but I get
operation not permitted as a result.
I tried to understand what's going on in the driver and found out that
timeout occurs.

As a consequence, I'd like to get something clear to me:
Since ICH9 supports 32-Byte Buffer (E32B) and according to the data
sheet the DS bit of the HST_STS is meaningless when E32B is enabled
and it's (E32B) enabled by the i801 driver.
On the other hand, in i801_check_pre called (from
i801_block_transaction_by_block) the macro STATUS_FLAGS verifies the
DS bit (designated as SMBHSTSTS_BYTE_DONE in the code).
Looking at the previous version of the driver, like in 2.5.25 there
was a mask 0x1f but it has gone since.
Is this behavior correct?

And another question related. Have you/anyone tried to output I2C
write transaction of arbitrary length, i.e. DATA0 is not sent on the
bus, from ICH9?

Thank you in advance,
Felix R.


On Fri, Feb 19, 2010 at 11:58 AM, Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org> wrote:
> Hi Felix,
>
> On Fri, 19 Feb 2010 09:10:03 +0200, Felix Rubinstein wrote:
>> Does ICHx support straight I2C read of arbitrary length, i.e. without doing
>> write first?
>
> No, it doesn't. The only straight read lengths supported are 0 byte
> (SMBus quick command) and 1 byte (SMBus receive byte).
>
> --
> Jean Delvare
> http://khali.linux-fr.org/wishlist.html
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