From: wellsk40@gmail.com (Kevin Wells)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4] GPIO PL061: Adding Clk framework support
Date: Tue, 3 Aug 2010 13:36:25 -0700 [thread overview]
Message-ID: <AANLkTimcunSmSiV2+N19RPbZ_AwfzEnAMyO74Zh+N6h7@mail.gmail.com> (raw)
In-Reply-To: <AANLkTi=mtdcsr+KBUuK2rA1zrbcRRdCj1PvuSDrUjke-@mail.gmail.com>
> 2010/8/3 Kevin Wells <kevin.wells@nxp.com>:
>
>> Wouldn't drivers that use clk_disable in their xxx_suspend functions
>> have some problems with this as multiple clk_enables have been called?
>
> Russell already answered that, all drivers have to be augmented
> in the following way (this is for PL011, the same will be valid for
> any other PrimeCell with aggressive clocking):
>
> [Russell King]
>> 1. add an amba_bus_clk_disable() at the end of the successful probe
>> ?function
>> 2. add amba_bus_clk_enable() at the beginning of the remove function.
>> 3. add amba_bus_clk_enable()/amba_bus_clk_disable() around each of the
>> suspend(), resume(), pl011_console_write(), and
>> ?pl011_console_get_options() functions.
>> 4. amba_bus_clk_enable() at the start of the startup method.
>> 5. amba_bus_clk_disable() at the end of the shutdown method.
>
>> AMBA enables clock in amba_probe() <<< clock use count = 1
>> pl022 driver enables clock in mmci_probe <<< clock use count = 2
>> ...SPI stuff happens...
>> ...Linux enters suspend mode...
>> pl022 driver enters suspend mode, disables clock <<< clock use count = 1
>
> OK I feel some responsibility for that driver so I will try to fix it,
> maybe I can take a round at PL011 and perhaps MMCI as well.
>
Thanks for the info Linus. I'll take an initial try at the pl11x driver..
Kevin
next prev parent reply other threads:[~2010-08-03 20:36 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-22 5:07 [PATCH v4] GPIO PL061: Adding Clk framework support Viresh KUMAR
2010-06-22 17:06 ` Baruch Siach
2010-07-09 12:40 ` Russell King - ARM Linux
2010-07-09 23:55 ` Linus Walleij
2010-07-10 7:19 ` Russell King - ARM Linux
2010-07-10 7:30 ` Russell King - ARM Linux
2010-07-10 15:36 ` Linus Walleij
2010-07-13 7:44 ` Russell King - ARM Linux
2010-07-13 11:00 ` Linus Walleij
2010-07-13 18:26 ` Russell King - ARM Linux
2010-07-15 6:02 ` Viresh KUMAR
2010-07-15 8:30 ` Russell King - ARM Linux
2010-07-15 9:35 ` Viresh KUMAR
2010-07-15 9:44 ` Linus Walleij
2010-07-15 9:56 ` Russell King - ARM Linux
2010-07-15 16:09 ` Rabin Vincent
2010-07-15 16:22 ` Russell King - ARM Linux
2010-07-29 23:22 ` Kevin Wells
2010-07-30 7:09 ` Russell King - ARM Linux
2010-08-03 0:40 ` Kevin Wells
2010-08-03 13:00 ` Linus Walleij
2010-08-03 20:36 ` Kevin Wells [this message]
2010-08-03 21:23 ` Russell King - ARM Linux
2010-07-30 15:19 ` Linus Walleij
2010-07-12 4:07 ` Viresh KUMAR
2010-07-12 7:53 ` Linus Walleij
2010-07-12 8:07 ` Russell King - ARM Linux
2010-07-12 8:18 ` Viresh KUMAR
2010-07-12 8:34 ` Russell King - ARM Linux
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=AANLkTimcunSmSiV2+N19RPbZ_AwfzEnAMyO74Zh+N6h7@mail.gmail.com \
--to=wellsk40@gmail.com \
--cc=linux-arm-kernel@lists.infradead.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).