Re: [PATCH v2] HID: cp2112: support i2c write-read transfers in hid-cp2112

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Jul 10, 2015 at 5:21 PM, Jiri Kosina <jkosina@xxxxxxxx> wrote:
> On Thu, 9 Jul 2015, Ellen Wang wrote:
>
>> cp2112_i2c_xfer() only supports a single i2c_msg.  More than
>> one message at a time just returns EIO.  This breaks certain
>> important cases.  For example, the at24 eeprom driver generates
>> paired write and read messages (for eeprom address and data).
>>
>> Since the device doesn't support i2c repeated starts in general,
>> but does support a single write-repeated-start-read pair
>> (since hardware rev 1), we recognize the latter case and
>> implement only that.
>>
>> Signed-off-by: Ellen Wang <ellen@xxxxxxxxxxxxxxxxxxx>
>
> Applied to for-4.3/cp2112.
>

Good!

Either
Tested-by: Antonio Borneo <borneo.antonio@xxxxxxxxx>
and/or
Reviewed-by: Antonio Borneo <borneo.antonio@xxxxxxxxx>

By the way, while this patch extends the i2c functionality, it makes
clear that repeated start is always broken on HW rev 1, also for
SMBUS!
I'm testing a patch to restrict SMBUS on rev 1 to only those
transactions that don't require repeated start.
Will post it shortly.

Regards,
Antonio
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Media Devel]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Linux Wireless Networking]     [Linux Omap]

  Powered by Linux