From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Keguang Zhang <keguang.zhang@gmail.com>
Cc: Keguang Zhang via B4 Relay
<devnull+keguang.zhang.gmail.com@kernel.org>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
devicetree@vger.kernel.org, linux-media@vger.kernel.org
Subject: Re: [PATCH v11 2/2] mtd: rawnand: Add Loongson-1 NAND Controller Driver
Date: Mon, 20 Jan 2025 09:10:04 +0100 [thread overview]
Message-ID: <874j1tykgz.fsf@bootlin.com> (raw)
In-Reply-To: <CAJhJPsVhH=8dKmUgmTSHnG8H1_9G3zvovX9hDv_VM6fSUR5oQw@mail.gmail.com> (Keguang Zhang's message of "Sat, 18 Jan 2025 16:01:19 +0800")
>> >> Don't you need a dma_addr_t here instead? You shall remap the resource.
>> >>
>> > Sorry, I don't quite understand.
>> > 'dma_base' is already of type dma_addr_t.
>>
>> I didn't identify where the dma_base was remapped, but if that's already
>> done then we're good.
>
> Perhaps I misunderstand the usage of dma_map_resource(). dma_base is
> the physical address and will be written to the DMA controller
> register at last.
IIUC, yes and no. It is the remapped address of the physical address you
want to reach, not the physical address itself. The type is dma_addr_t
and not phys_addr_t and you can get a dma address out of a physical
address with a call to dma_map_resource(). The numerical value might be
the same if there is no IO-MMU involved, but the good practice is to
remap anyway.
Thanks,
Miquèl
next prev parent reply other threads:[~2025-01-20 8:10 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-17 10:16 [PATCH v11 0/2] Add support for Loongson-1 NAND Keguang Zhang via B4 Relay
2024-12-17 10:16 ` [PATCH v11 1/2] dt-bindings: mtd: Add Loongson-1 NAND Controller Keguang Zhang via B4 Relay
2024-12-18 9:01 ` Krzysztof Kozlowski
2024-12-18 9:31 ` Keguang Zhang
2024-12-17 10:16 ` [PATCH v11 2/2] mtd: rawnand: Add Loongson-1 NAND Controller Driver Keguang Zhang via B4 Relay
2025-01-15 18:54 ` Miquel Raynal
2025-01-17 11:58 ` Keguang Zhang
2025-01-17 18:26 ` Miquel Raynal
2025-01-18 8:01 ` Keguang Zhang
2025-01-20 8:10 ` Miquel Raynal [this message]
2025-01-20 11:08 ` Keguang Zhang
2025-01-20 12:54 ` Miquel Raynal
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