* question about concurrent regmap i2c usage
@ 2017-04-04 8:28 Michael Hennerich
2017-04-04 12:26 ` Mark Brown
0 siblings, 1 reply; 3+ messages in thread
From: Michael Hennerich @ 2017-04-04 8:28 UTC (permalink / raw)
To: broonie, ", linus.walleij", wsa
Cc: linux-gpio, linux-i2c, linux-kernel
Hi Mark,
During the discussion here: https://lkml.org/lkml/2017/4/4/76
A question came up, regarding whether it's recommended to mix regmap_i2c
and plain i2c_smbus or direct adapter transfers.
In this specific case for the i2c MUX portion we need to avoid double
locks, and therefore use un-locked direct adapter transfers.
The same time we also implement a small gpiochip, where we would like to
use regmap to avoid some boilerplate code for the register cache.
What is your thought on this?
--
Greetings,
Michael
--
Analog Devices GmbH Otl-Aicher Strasse 60-64 80807 München
Sitz der Gesellschaft München, Registergericht München HRB 40368,
Geschäftsführer: Peter Kolberg, Ali Raza Husain, Eileen Wynne
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: question about concurrent regmap i2c usage
2017-04-04 8:28 question about concurrent regmap i2c usage Michael Hennerich
@ 2017-04-04 12:26 ` Mark Brown
2017-04-05 6:31 ` Michael Hennerich
0 siblings, 1 reply; 3+ messages in thread
From: Mark Brown @ 2017-04-04 12:26 UTC (permalink / raw)
To: Michael Hennerich; +Cc: linus.walleij, wsa, linux-gpio, linux-i2c, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 631 bytes --]
On Tue, Apr 04, 2017 at 10:28:23AM +0200, Michael Hennerich wrote:
> A question came up, regarding whether it's recommended to mix regmap_i2c and
> plain i2c_smbus or direct adapter transfers.
> In this specific case for the i2c MUX portion we need to avoid double locks,
> and therefore use un-locked direct adapter transfers.
> The same time we also implement a small gpiochip, where we would like to use
> regmap to avoid some boilerplate code for the register cache.
That should work fine providing nothing tries to change cached registers
underneath the regmap. regmap won't be able to tell anything's changed
otherwise.
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: question about concurrent regmap i2c usage
2017-04-04 12:26 ` Mark Brown
@ 2017-04-05 6:31 ` Michael Hennerich
0 siblings, 0 replies; 3+ messages in thread
From: Michael Hennerich @ 2017-04-05 6:31 UTC (permalink / raw)
To: Mark Brown; +Cc: linus.walleij, wsa, linux-gpio, linux-i2c, linux-kernel
On 04.04.2017 14:26, Mark Brown wrote:
> On Tue, Apr 04, 2017 at 10:28:23AM +0200, Michael Hennerich wrote:
>
>> A question came up, regarding whether it's recommended to mix regmap_i2c and
>> plain i2c_smbus or direct adapter transfers.
>
>> In this specific case for the i2c MUX portion we need to avoid double locks,
>> and therefore use un-locked direct adapter transfers.
>
>> The same time we also implement a small gpiochip, where we would like to use
>> regmap to avoid some boilerplate code for the register cache.
>
> That should work fine providing nothing tries to change cached registers
> underneath the regmap. regmap won't be able to tell anything's changed
> otherwise.
Hi Mark,
Thanks for confirmation!
--
Greetings,
Michael
--
Analog Devices GmbH Otl-Aicher Strasse 60-64 80807 München
Sitz der Gesellschaft München, Registergericht München HRB 40368,
Geschäftsführer: Peter Kolberg, Ali Raza Husain, Eileen Wynne
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-04-05 6:29 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-04-04 8:28 question about concurrent regmap i2c usage Michael Hennerich
2017-04-04 12:26 ` Mark Brown
2017-04-05 6:31 ` Michael Hennerich
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).