From: Guenter Roeck <linux@roeck-us.net>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>, linux-usb@vger.kernel.org
Subject: Re: [PATCH 1/7] usb: typec: Copy everything from struct typec_capability during registration
Date: Wed, 2 Oct 2019 20:45:28 -0700 [thread overview]
Message-ID: <318179e6-fa1e-0b33-4a4f-40ecd6947f8a@roeck-us.net> (raw)
In-Reply-To: <20191002182933.GA19870@kuha.fi.intel.com>
On 10/2/19 11:29 AM, Heikki Krogerus wrote:
> On Wed, Oct 02, 2019 at 09:36:39AM -0700, Guenter Roeck wrote:
>> port->cap->type used to be the role provided by the low level driver.
>> That was static, and it was not possible to override it. It did not
>> resemble the current port type, or a configured port type, it resembled
>> port capabilities.
>>
>> Your code changes that, meaning even if the low level driver (effectively
>> the hardware) states that it can not support DRP, it is now configurable
>> anyway. That seems to me like a substantial change to the original meaning
>> of this attribute.
>>
>> Effectiv ely there are now three values,
>> - port->port_type the current port tyle
>> - port->fixed_type the type selected by the user
>> - port->cap->type the type provided by low level code,
>> now no longer available / used
>>
>> Even if the low level driver (hardware) says that it can not support
>> TYPEC_PORT_DRP, that can be overwritten by the user. Maybe there is a
>> good reason for that, but I don't see it, sorry.
>
> No, that was not my intention. Clearly there is a bug in my code.
>
>> Maybe it would make sense to introduce port->fixed_type in a separate patch.
>> As part of that patch you could explain why port->cap->type, ie a reflection
>> of the port capabilities, is no longer needed.
>
> Or, I could make this really simple. I could just copy the content of
> the cap as is to another struct typec_capability during port
> registration. My goal is really just remove the need for the device
> drivers keep the struct typec_capability instance if they don't need
> it, and I don't need to remove the cap member to achieve that.
>
Maybe just use devm_kmemdup() ?
Guenter
> Nevertheless, IMO this attribute file really needs to be deprecated.
> On top of making things unnecessarily complicated for the userspace,
> it's making it difficult to make changes to the rest of the class
> code. We may not be able to get rid of the file, but there is nothing
> preventing us from supplying a better solution as an option.
>
next prev parent reply other threads:[~2019-10-03 3:45 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-01 9:48 [PATCH 0/7] usb: typec: Small API improvement Heikki Krogerus
2019-10-01 9:48 ` [PATCH 1/7] usb: typec: Copy everything from struct typec_capability during registration Heikki Krogerus
2019-10-01 13:08 ` Guenter Roeck
2019-10-02 16:06 ` Heikki Krogerus
2019-10-02 16:36 ` Guenter Roeck
2019-10-02 18:29 ` Heikki Krogerus
2019-10-03 3:45 ` Guenter Roeck [this message]
2019-10-03 8:03 ` Heikki Krogerus
2019-10-02 19:16 ` Heikki Krogerus
2019-10-03 3:51 ` Guenter Roeck
2019-10-03 13:29 ` Heikki Krogerus
2019-10-01 9:48 ` [PATCH 2/7] usb: typec: Introduce typec_get_drvdata() Heikki Krogerus
2019-10-01 9:48 ` [PATCH 3/7] usb: typec: Separate the operations vector Heikki Krogerus
2019-10-01 13:22 ` Guenter Roeck
2019-10-04 8:45 ` Heikki Krogerus
2019-10-01 9:48 ` [PATCH 4/7] usb: typec: tcpm: Start using struct typec_operations Heikki Krogerus
2019-10-01 13:30 ` Guenter Roeck
2019-10-04 8:46 ` Heikki Krogerus
2019-10-01 9:48 ` [PATCH 5/7] usb: typec: tps6598x: " Heikki Krogerus
2019-10-01 13:34 ` Guenter Roeck
2019-10-01 13:35 ` Guenter Roeck
2019-10-04 8:49 ` Heikki Krogerus
2019-10-01 9:48 ` [PATCH 6/7] usb: typec: ucsi: " Heikki Krogerus
2019-10-01 13:35 ` Guenter Roeck
2019-10-01 9:48 ` [PATCH 7/7] usb: typec: Remove the callback members from struct typec_capability Heikki Krogerus
2019-10-01 13:37 ` Guenter Roeck
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=318179e6-fa1e-0b33-4a4f-40ecd6947f8a@roeck-us.net \
--to=linux@roeck-us.net \
--cc=hdegoede@redhat.com \
--cc=heikki.krogerus@linux.intel.com \
--cc=linux-usb@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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).