From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 929521D79BE; Mon, 2 Dec 2024 16:52:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733158371; cv=none; b=fHcRYolvlz/CwZ6ZlxxpEFiRWUiG39/vCcVMa1oSx4ysA2uMJ/7zF5/iBfrEvGEbhSFj/SgzFBycE4V+RuszMTfJ5zKmDdoPbN5EUcv4xUI51XifixgA574X7mA8WUXA8kfbqCzao3hHR3npJg5ED8FbEBDfg0vqU8fnf29L7b0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733158371; c=relaxed/simple; bh=Q4lgsKkUPNBCVPx2h6Wla6/xJs8K53Ur7RI1wCNcloo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=d/coeqsC6xCKPOq/rbg2rhAvQeAOf7nDC5/BgE3v/EirvbXP+HFciGEqxmVqsoQkJ2YQp16TS16Fbd3y320zlTaitfRqTMXLcwDoVT3l0UIJvfpdR8F6hW+wyQ8G5cL99yDrvlrWY85xjglOMzRurBl42XqX7ai9OuzNqO9EwKk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=i7eCKFg1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="i7eCKFg1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE0C7C4CED1; Mon, 2 Dec 2024 16:52:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733158371; bh=Q4lgsKkUPNBCVPx2h6Wla6/xJs8K53Ur7RI1wCNcloo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=i7eCKFg1KXaaddaBtfqvXEQXCx2za65xSHDAg3p8iOSCWY6ytSNVv12kFL7z7CWvq 0DMDJHotcWDgEDTMj4PylU1/giO6ZMrur/AUevxXMWfJF2QSKA3PdTnFBuglYs9v1l zCVze3VgoxR4wEK0qEngPtu4l8FdTi7N57nYrhTLhhuUiGnk52yUwNHMtO6TRkLpKD UO1NIPx7IyPzKssU3ntLNZQ0wOGJoLJEbIu5NOn9z91bBvHGpBiuRqU9SfQfDX5wWr 2rARLFekFQxrlVxy3Fzeu/aF4tQcZku6YYQMY6hDpWKslOmAWnZO0V9FbFOSRigjCM 3xbcYpmeBH+9Q== Date: Mon, 2 Dec 2024 22:22:47 +0530 From: Vinod Koul To: Stefan Wahren Cc: Russell King , Florian Fainelli , Ray Jui , Scott Branden , Ulf Hansson , Minas Harutyunyan , Greg Kroah-Hartman , Lukas Wunner , Peter Robinson , "Ivan T . Ivanov" , linux-arm-kernel@lists.infradead.org, kernel-list@raspberrypi.com, bcm-kernel-feedback-list@broadcom.com, dmaengine@vger.kernel.org, linux-mmc@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCH V5 2/9] dmaengine: bcm2835-dma: add suspend/resume pm support Message-ID: References: <20241025103621.4780-1-wahrenst@gmx.net> <20241025103621.4780-3-wahrenst@gmx.net> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241025103621.4780-3-wahrenst@gmx.net> On 25-10-24, 12:36, Stefan Wahren wrote: > bcm2835-dma provides the service to others, so it should > suspend late and resume early. > > Signed-off-by: Stefan Wahren > --- > drivers/dma/bcm2835-dma.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c > index e1b92b4d7b05..647dda9f3376 100644 > --- a/drivers/dma/bcm2835-dma.c > +++ b/drivers/dma/bcm2835-dma.c > @@ -875,6 +875,35 @@ static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec, > return chan; > } > > +static int bcm2835_dma_suspend_late(struct device *dev) > +{ > + struct bcm2835_dmadev *od = dev_get_drvdata(dev); > + struct bcm2835_chan *c, *next; > + > + list_for_each_entry_safe(c, next, &od->ddev.channels, > + vc.chan.device_node) { > + void __iomem *chan_base = c->chan_base; > + > + if (readl(chan_base + BCM2835_DMA_ADDR)) { > + dev_warn(dev, "Suspend is prevented by chan %d\n", > + c->ch); > + return -EBUSY; > + } Can you help understand how this helps by logging... we are not adding anything except checking this and resume is NOP as well! > + } > + > + return 0; > +} > + > +static int bcm2835_dma_resume_early(struct device *dev) > +{ > + return 0; > +} > + > +static const struct dev_pm_ops bcm2835_dma_pm_ops = { > + SET_LATE_SYSTEM_SLEEP_PM_OPS(bcm2835_dma_suspend_late, > + bcm2835_dma_resume_early) > +}; > + > static int bcm2835_dma_probe(struct platform_device *pdev) > { > struct bcm2835_dmadev *od; > @@ -1033,6 +1062,7 @@ static struct platform_driver bcm2835_dma_driver = { > .driver = { > .name = "bcm2835-dma", > .of_match_table = of_match_ptr(bcm2835_dma_of_match), > + .pm = pm_ptr(&bcm2835_dma_pm_ops), > }, > }; > > -- > 2.34.1 -- ~Vinod