Re: [PATCH v4 02/10] dmaengine: Actions: Add support for S700 DMA engine

From: Vinod Koul <vkoul@kernel.org>
To: Amit Tomer <amittomer25@gmail.com>
Cc: "Andre Przywara" <andre.przywara@arm.com>,
	linux-actions@lists.infradead.org, linux-kernel@vger.kernel.org,
	cristian.ciocaltea@gmail.com,
	"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>,
	dmaengine@vger.kernel.org, dan.j.williams@intel.com,
	"Andreas Färber" <afaerber@suse.de>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v4 02/10] dmaengine: Actions: Add support for S700 DMA engine
Date: Tue, 30 Jun 2020 19:54:27 +0530	[thread overview]
Message-ID: <20200630142427.GP2599@vkoul-mobl> (raw)
In-Reply-To: <CABHD4K9VOWpC7=o2VKrqoxEtMQ2gFv_Qs885dBKL1o+B_fe_3g@mail.gmail.com>

On 30-06-20, 15:17, Amit Tomer wrote:
> Hi Vinod,
> 
> On Mon, Jun 29, 2020 at 3:22 PM Vinod Koul <vkoul@kernel.org> wrote:
> 
> > If you use of_device_get_match_data() you will not fall into this :)
> 
> But again, of_device_get_match_data() returns void *, and we need
> "uintptr_t" in order to type cast it properly (at-least without
> warning).

Not really, you can cast from void * to you own structure.. btw why do
you need uintptr_t?

> 
> Also, while looking around found the similar warning for other file
> where it uses " of_device_get_match_data()"
> drivers/pci/controller/pcie-iproc-platform.c:56:15: warning: cast to
> smaller integer type 'enum iproc_pcie_type' from 'const void *'
> [-Wvoid-pointer-to-enum-cast]
>         pcie->type = (enum iproc_pcie_type) of_device_get_match_data(dev);

The problem is a pointer to enum conversion :) I think the right way
would be to do would be below

        soc_type =  (enum foo)of_device_get_match_data(dev);

or
        soc_type =  (unsigned long) of_device_get_match_data(dev);

which I think should be fine in gcc, but possibly give you above warning
in clang.. but i thought that was fixed in clang https://reviews.llvm.org/D75758

Thanks
-- 
~Vinod

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