All of lore.kernel.org
 help / color / mirror / Atom feed
From: Tony Lindgren <tony@atomide.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>,
	Lukas Bulwahn <lukas.bulwahn@gmail.com>,
	Janusz Krzysztofik <jmkrzyszt@gmail.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	linux-arm-kernel@lists.infradead.org,
	Linux-OMAP <linux-omap@vger.kernel.org>,
	linux-usb@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
	kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/4] usb: remove OMAP USB Device Controller and OHCI support for OMAP1/2 chips
Date: Fri, 13 Jan 2023 09:14:30 +0200	[thread overview]
Message-ID: <Y8EE1qQ3uArtYc+w@atomide.com> (raw)
In-Reply-To: <179739a0-5d75-412b-964b-16d5cb6d306d@app.fastmail.com>

* Arnd Bergmann <arnd@arndb.de> [230112 14:31]:
> On Thu, Jan 12, 2023, at 15:05, Aaro Koskinen wrote:
> > On Thu, Jan 12, 2023 at 11:19:53AM +0100, Arnd Bergmann wrote:
> >> On Thu, Jan 12, 2023, at 10:53, Tony Lindgren wrote:
> >> 
> >> So if we want to kill off the old DMA stuff there is actually
> >> a choice between either making omap_udc PIO-only or converting
> >> it to use the standard dmaengine interface.
> >
> > I use this driver on Palm TE and 770, and without it those boards would
> > be useless for my use cases. Also DMA doubles the throughput, probably
> > also power usage is smaller.
> 
> Ok, if the performance is important, converting to dmaengine
> is probably best. Do you know if this is just a straightforward
> replacement of the function calls, or are there technical reasons
> why it's not using the dmaengine interface yet?

Yes I agree dmaengine is the best solution. Seems like this is the
last driver using the old api that never got updated probably because
it's not used on the newer SoCs.

I don't think there are any technical reasons to not use dmaengine
here.

FYI, the last blocker for dmaengine use was for drivers using
port_window that got added with the drivers/usb/musb/tusb6010_omap.c
dmaengine conversion a few years back.

Regards,

Tony

WARNING: multiple messages have this Message-ID (diff)
From: Tony Lindgren <tony@atomide.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>,
	Lukas Bulwahn <lukas.bulwahn@gmail.com>,
	Janusz Krzysztofik <jmkrzyszt@gmail.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	linux-arm-kernel@lists.infradead.org,
	Linux-OMAP <linux-omap@vger.kernel.org>,
	linux-usb@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
	kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/4] usb: remove OMAP USB Device Controller and OHCI support for OMAP1/2 chips
Date: Fri, 13 Jan 2023 09:14:30 +0200	[thread overview]
Message-ID: <Y8EE1qQ3uArtYc+w@atomide.com> (raw)
In-Reply-To: <179739a0-5d75-412b-964b-16d5cb6d306d@app.fastmail.com>

* Arnd Bergmann <arnd@arndb.de> [230112 14:31]:
> On Thu, Jan 12, 2023, at 15:05, Aaro Koskinen wrote:
> > On Thu, Jan 12, 2023 at 11:19:53AM +0100, Arnd Bergmann wrote:
> >> On Thu, Jan 12, 2023, at 10:53, Tony Lindgren wrote:
> >> 
> >> So if we want to kill off the old DMA stuff there is actually
> >> a choice between either making omap_udc PIO-only or converting
> >> it to use the standard dmaengine interface.
> >
> > I use this driver on Palm TE and 770, and without it those boards would
> > be useless for my use cases. Also DMA doubles the throughput, probably
> > also power usage is smaller.
> 
> Ok, if the performance is important, converting to dmaengine
> is probably best. Do you know if this is just a straightforward
> replacement of the function calls, or are there technical reasons
> why it's not using the dmaengine interface yet?

Yes I agree dmaengine is the best solution. Seems like this is the
last driver using the old api that never got updated probably because
it's not used on the newer SoCs.

I don't think there are any technical reasons to not use dmaengine
here.

FYI, the last blocker for dmaengine use was for drivers using
port_window that got added with the drivers/usb/musb/tusb6010_omap.c
dmaengine conversion a few years back.

Regards,

Tony

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2023-01-13  7:24 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-12  8:37 [PATCH 0/4] Further code removal after Arnd's latest cleanup Lukas Bulwahn
2023-01-12  8:37 ` Lukas Bulwahn
2023-01-12  8:37 ` [PATCH 1/4] ARM: s3c: remove obsolete s3c-cpu-freq header Lukas Bulwahn
2023-01-12  8:37   ` Lukas Bulwahn
2023-01-12  8:57   ` Krzysztof Kozlowski
2023-01-12  8:57     ` Krzysztof Kozlowski
2023-01-12  8:37 ` [PATCH 2/4] ARM: pxa: remove further dead code after pxa93 support removal Lukas Bulwahn
2023-01-12  8:37   ` Lukas Bulwahn
2023-01-12  9:05   ` Arnd Bergmann
2023-01-12  9:05     ` Arnd Bergmann
2023-01-12  9:26     ` Lukas Bulwahn
2023-01-12  9:26       ` Lukas Bulwahn
2023-01-12 10:30       ` Arnd Bergmann
2023-01-12 10:30         ` Arnd Bergmann
2023-01-12  8:37 ` [PATCH 3/4] usb: remove OMAP USB Device Controller and OHCI support for OMAP1/2 chips Lukas Bulwahn
2023-01-12  9:02   ` Arnd Bergmann
2023-01-12  9:02     ` Arnd Bergmann
2023-01-12  9:19     ` Lukas Bulwahn
2023-01-12  9:19       ` Lukas Bulwahn
2023-01-12  9:53       ` Arnd Bergmann
2023-01-12  9:53         ` Arnd Bergmann
2023-01-12  9:53     ` Tony Lindgren
2023-01-12  9:53       ` Tony Lindgren
2023-01-12 10:19       ` Arnd Bergmann
2023-01-12 10:19         ` Arnd Bergmann
2023-01-12 14:05         ` Aaro Koskinen
2023-01-12 14:05           ` Aaro Koskinen
2023-01-12 14:31           ` Arnd Bergmann
2023-01-12 14:31             ` Arnd Bergmann
2023-01-13  7:14             ` Tony Lindgren [this message]
2023-01-13  7:14               ` Tony Lindgren
2023-01-12  8:37 ` [PATCH 4/4] ARM: debug: remove references in DEBUG_UART_8250_SHIFT to removed configs Lukas Bulwahn
2023-01-12  8:37   ` Lukas Bulwahn

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=Y8EE1qQ3uArtYc+w@atomide.com \
    --to=tony@atomide.com \
    --cc=aaro.koskinen@iki.fi \
    --cc=arnd@arndb.de \
    --cc=jmkrzyszt@gmail.com \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=krzysztof.kozlowski@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=linux-samsung-soc@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=lukas.bulwahn@gmail.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 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.