Re: [PATCH 2/9] dma: Convert from tasklet to BH workqueue

From: Allen <allen.lkml@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: imx@lists.linux.dev, "Ulf Hansson" <ulf.hansson@linaro.org>,
	"Oliver Neukum" <oneukum@suse.com>,
	"Duncan Sands" <duncan.sands@free.fr>,
	"Kunihiko Hayashi" <hayashi.kunihiko@socionext.com>,
	"linux-mmc @ vger . kernel . org" <linux-mmc@vger.kernel.org>,
	aubin.constans@microchip.com,
	"Linus Walleij" <linus.walleij@linaro.org>,
	"Frank Li" <Frank.Li@nxp.com>,
	linux-hyperv@vger.kernel.org, linux-usb@vger.kernel.org,
	HaraldWelte@viatech.com, "Paul Cercueil" <paul@crapouillou.net>,
	linux-tegra@vger.kernel.org, Netdev <netdev@vger.kernel.org>,
	maintainers@bluecherrydvr.com, peter.ujfalusi@gmail.com,
	"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	linux-riscv@lists.infradead.org,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	"Robert Jarzmik" <robert.jarzmik@free.fr>,
	haijie1@huawei.com,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	"Wei Liu" <wei.liu@kernel.org>,
	Linux-OMAP <linux-omap@vger.kernel.org>,
	"Florian Fainelli" <florian.fainelli@broadcom.com>,
	linux-rdma@vger.kernel.org
Subject: Re: [PATCH 2/9] dma: Convert from tasklet to BH workqueue
Date: Thu, 28 Mar 2024 13:01:55 -0700	[thread overview]
Message-ID: <CAOMdWSKC4B8zn6N+=5DssB_BiR6JkHBEpJr0ohKb149eJvCKMQ@mail.gmail.com> (raw)
In-Reply-To: <678ba20b-9f1d-41cb-8a25-e716b61ffafe@app.fastmail.com>

> >> > Since almost every driver associates the tasklet with the
> >> > dma_chan, we could go one step further and add the
> >> > work_queue structure directly into struct dma_chan,
> >> > with the wrapper operating on the dma_chan rather than
> >> > the work_queue.
> >>
> >> I think that is very great idea. having this wrapped in dma_chan would
> >> be very good way as well
> >>
> >> Am not sure if Allen is up for it :-)
> >
> >  Thanks Arnd, I know we did speak about this at LPC. I did start
> > working on using completion. I dropped it as I thought it would
> > be easier to move to workqueues.
>
> It's definitely easier to do the workqueue conversion as a first
> step, and I agree adding support for the completion right away is
> probably too much. Moving the work_struct into the dma_chan
> is probably not too hard though, if you leave your current
> approach for the cases where the tasklet is part of the
> dma_dev rather than the dma_chan.
>

 Alright, I will work on moving work_struck into the dma_chan and
leave the dma_dev as is (using bh workqueues) and post a RFC.
Once reviewed, I could move to the next step.

Thank you.

- Allen