From: Florian Fainelli <f.fainelli@gmail.com>
To: Lukas Wunner <lukas@wunner.de>
Cc: linux-kernel@vger.kernel.org, Mark Brown <broonie@kernel.org>,
Ray Jui <rjui@broadcom.com>,
Scott Branden <sbranden@broadcom.com>,
"maintainer:BROADCOM BCM281XX/BCM11XXX/BCM216XX ARM ARCHITE..."
<bcm-kernel-feedback-list@broadcom.com>,
Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
"open list:SPI SUBSYSTEM" <linux-spi@vger.kernel.org>,
"moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE"
<linux-rpi-kernel@lists.infradead.org>,
"moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] spi: bcm2835: Implement shutdown callback
Date: Fri, 29 May 2020 11:04:36 -0700 [thread overview]
Message-ID: <7299c445-4d26-06ce-9073-8ac0f32e590e@gmail.com> (raw)
In-Reply-To: <20200529175831.p4dphb5luymgapzx@wunner.de>
On 5/29/20 10:58 AM, Lukas Wunner wrote:
> On Fri, May 29, 2020 at 10:48:11AM -0700, Florian Fainelli wrote:
>> On 5/29/20 10:47 AM, Lukas Wunner wrote:
>>> On Thu, May 28, 2020 at 12:06:05PM -0700, Florian Fainelli wrote:
>>>> Make sure we clear the FIFOs, stop the block, disable the clock and
>>>> release the DMA channel.
>>>
>>> To what end? Why is this change necessary? Sorry but this seems like
>>> an awfully terse commit message.
>>
>> To ensure clocks are disabled and to save power in low power modes used
>> on 7211 for instance.
>
> Thanks for the explanation, that's an important tidbit. I wasn't even
> aware that this SPI controller is used on SoCs beyond the Raspberry Pi
> ones. Does the BCM7211 use shared interrupts for this controller?
> Does it have DMA DREQ attached?
For all practical purposes you can consider that 7211 is identical to a
2711, it does use shared interrupts for this controller and there is a
DRAM DREQ attached as well. Where they differ are on the display, video,
and memory controller MAC.
--
Florian
prev parent reply other threads:[~2020-05-29 18:04 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-28 19:06 [PATCH] spi: bcm2835: Implement shutdown callback Florian Fainelli
2020-05-29 17:18 ` Mark Brown
2020-05-29 17:47 ` Lukas Wunner
2020-05-29 17:48 ` Florian Fainelli
2020-05-29 17:58 ` Lukas Wunner
2020-05-29 18:04 ` Florian Fainelli [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=7299c445-4d26-06ce-9073-8ac0f32e590e@gmail.com \
--to=f.fainelli@gmail.com \
--cc=bcm-kernel-feedback-list@broadcom.com \
--cc=broonie@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rpi-kernel@lists.infradead.org \
--cc=linux-spi@vger.kernel.org \
--cc=lukas@wunner.de \
--cc=nsaenzjulienne@suse.de \
--cc=rjui@broadcom.com \
--cc=sbranden@broadcom.com \
/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).