linux-kernel - Re: [PATCH v3 2/5] dmaengine: Add STM32 DMAMUX driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 26 Jul 2017 10:59:31 +0530
From:   Vinod Koul <vinod.koul@...el.com>
To:     Pierre Yves MORDRET <pierre-yves.mordret@...com>
Cc:     Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Alexandre TORGUE <alexandre.torgue@...com>,
        Russell King <linux@...linux.org.uk>,
        Dan Williams <dan.j.williams@...el.com>,
        M'boumba Cedric Madianga <cedric.madianga@...il.com>,
        Fabrice GASNIER <fabrice.gasnier@...com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Fabien DESSENNE <fabien.dessenne@...com>,
        Amelie DELAUNAY <amelie.delaunay@...com>,
        "dmaengine@...r.kernel.org" <dmaengine@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 2/5] dmaengine: Add STM32 DMAMUX driver

On Mon, Jul 24, 2017 at 01:55:10PM +0000, Pierre Yves MORDRET wrote:

> >> +
> >> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> +	if (!res)
> >> +		return -ENODEV;
> >> +
> >> +	iomem = devm_ioremap_resource(&pdev->dev, res);
> >> +	if (!iomem)
> >> +		return -ENOMEM;
> >> +
> >> +	spin_lock_init(&stm32_dmamux->lock);
> >> +
> >> +	stm32_dmamux->clk = devm_clk_get(&pdev->dev, NULL);
> >> +	if (IS_ERR(stm32_dmamux->clk)) {
> >> +		dev_info(&pdev->dev, "Missing controller clock\n");
> > 
> > Can you check for EPROBE_DEFER and print only for if that is not the error
> > otherwise we end up sapmming with defered probe issues
> > 
> 
> This is what you meant ?
> 	if (IS_ERR(stm32_dmamux->clk) != EPROBE_DEFER) {
> 		dev_info(&pdev->dev, "Missing controller clock\n");
> 		return PTR_ERR(stm32_dmamux->clk);
> 	}
> 
> OR
> 
> 	if (IS_ERR(stm32_dmamux->clk)) {
> 		if (IS_ERR(stm32_dmamux->clk) != EPROBE_DEFER)
> 			dev_info(&pdev->dev, "Missing controller clock\n");
> 		return PTR_ERR(stm32_dmamux->clk);
> 	}

This one please

> 
> >> +
> >> +#ifndef __DMA_STM32_DMAMUX_H
> >> +#define __DMA_STM32_DMAMUX_H
> >> +
> >> +#if defined(CONFIG_STM32_DMAMUX)
> >> +int stm32_dmamux_set_config(struct device *dev, void *route_data, u32 chan_id);
> > 
> > Why do we need a custom API in this case?
> > 
> 
> This API is called by DMA when a slave is requested by client. DMA can work
> without DMAMUX this API has been put in place to configure DMAMUX whether client
> is requesting a DMAMUX Channel instead of a DMA one.

You mean the dmaengine driver right?

-- 
~Vinod