From: Vignesh Raghavendra <vigneshr@ti.com>
To: Miquel Raynal <miquel.raynal@bootlin.com>,
Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: <linux-mtd@lists.infradead.org>, <kbuild-all@lists.01.org>,
kernel test robot <lkp@intel.com>,
Serge Semin <fancer.lancer@gmail.com>,
<linux-kernel@vger.kernel.org>
Subject: Re: drivers/mtd/maps/physmap-bt1-rom.c:78:18: sparse: sparse: cast removes address space '__iomem' of expression
Date: Thu, 12 Nov 2020 20:30:42 +0530 [thread overview]
Message-ID: <8cdc6166-7183-c8a9-5c27-93a511e6471a@ti.com> (raw)
In-Reply-To: <20201112092715.7e466405@xps13>
On 11/12/20 1:57 PM, Miquel Raynal wrote:
> Hi Sergey,
>
> Serge Semin <Sergey.Semin@baikalelectronics.ru> wrote on Wed, 11 Nov
> 2020 22:22:59 +0300:
>
>> On Tue, Nov 10, 2020 at 04:35:56PM +0100, Miquel Raynal wrote:
>>> Hi Serge,
>>>
>>> Serge Semin <Sergey.Semin@baikalelectronics.ru> wrote on Tue, 10 Nov
>>> 2020 14:38:27 +0300:
>>>
>>>> Hello Miquel,
>>>>
>>>> A situation noted by the warning below won't cause any problem because
>>>> the casting is done to a non-dereferenced variable. It is utilized
>>>> as a pointer bias later in that function. Shall we just ignore the
>>>> warning or still fix it somehow?
>>>
>>
>>> Do you think the cast to a !__iomem value is mandatory here?
>>
>> It's not mandatory to have the casting with no __iomem, but wouldn't
>> doing like this:
>> + shift = (ssize_t __iomem)src & 0x3;
>> be looking weird? Really, is there a good way to somehow extract the first
>> two bits of a __iomem pointer without getting the sparse warning?
>
> I asked around me, what about trying uintptr_t?
>
One more way is to use __force to tell sparse that this casting is
intentional:
shift = (__force ssize_t)src & 0x3;
> Thanks,
> Miquèl
>
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
>
next prev parent reply other threads:[~2020-11-12 15:01 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-02 4:42 drivers/mtd/maps/physmap-bt1-rom.c:78:18: sparse: sparse: cast removes address space '__iomem' of expression kernel test robot
2020-11-10 11:38 ` Serge Semin
2020-11-10 15:35 ` Miquel Raynal
2020-11-11 19:22 ` Serge Semin
2020-11-12 8:27 ` Miquel Raynal
2020-11-12 11:20 ` Serge Semin
2020-11-12 15:00 ` Vignesh Raghavendra [this message]
2020-11-12 15:27 ` Serge Semin
2020-11-12 15:43 ` Miquel Raynal
2020-11-12 16:10 ` Serge Semin
2020-11-12 16:15 ` Miquel Raynal
2020-11-12 16:21 ` Serge Semin
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