From: Antonio Borneo <borneo.antonio@gmail.com>
To: Jiri Kosina <jkosina@suse.com>
Cc: Ellen Wang <ellen@cumulusnetworks.com>,
David Barksdale <dbarksdale@uplogix.com>,
linux-input <linux-input@vger.kernel.org>,
linux-i2c@vger.kernel.org
Subject: Re: [PATCH v2] HID: cp2112: support i2c write-read transfers in hid-cp2112
Date: Tue, 14 Jul 2015 18:09:57 +0800 [thread overview]
Message-ID: <CAAj6DX39n2kg67uG0uwVeKRGK20M33NtF+dH-_Fi2BBOkFq4pQ@mail.gmail.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1507101120570.14897@pobox.suse.cz>
On Fri, Jul 10, 2015 at 5:21 PM, Jiri Kosina <jkosina@suse.com> 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@cumulusnetworks.com>
>
> Applied to for-4.3/cp2112.
>
Good!
Either
Tested-by: Antonio Borneo <borneo.antonio@gmail.com>
and/or
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
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
prev parent reply other threads:[~2015-07-14 10:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-10 4:55 [PATCH v2] HID: cp2112: support i2c write-read transfers in hid-cp2112 Ellen Wang
2015-07-10 9:21 ` Jiri Kosina
2015-07-14 10:09 ` Antonio Borneo [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAAj6DX39n2kg67uG0uwVeKRGK20M33NtF+dH-_Fi2BBOkFq4pQ@mail.gmail.com \
--to=borneo.antonio@gmail.com \
--cc=dbarksdale@uplogix.com \
--cc=ellen@cumulusnetworks.com \
--cc=jkosina@suse.com \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-input@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.