Re: [PATCH] dma-mapping: move hint unlikely for dma_mapping_error from drivers to core

From: Wolfram Sang <wsa@kernel.org>
To: Heiner Kallweit <hkallweit1@gmail.com>
Cc: George Cherian <gcherian@marvell.com>,
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Subject: Re: [PATCH] dma-mapping: move hint unlikely for dma_mapping_error from drivers to core
Date: Thu, 10 Dec 2020 20:58:55 +0100	[thread overview]
Message-ID: <20201210195855.GA11120@kunai> (raw)
In-Reply-To: <5d08af46-5897-b827-dcfb-181d869c8f71@gmail.com>

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On Thu, Dec 10, 2020 at 03:47:50PM +0100, Heiner Kallweit wrote:
> Zillions of drivers use the unlikely() hint when checking the result of
> dma_mapping_error(). This is an inline function anyway, so we can move
> the hint into the function and remove it from drivers.
> From time to time discussions pop up how effective unlikely() is,
> and that it should be used only if something is really very unlikely.
> I think that's the case here.
> 
> Patch was created with some help from coccinelle.
> 
> @@
> expression dev, dma_addr;
> @@
> 
> - unlikely(dma_mapping_error(dev, dma_addr))
> + dma_mapping_error(dev, dma_addr)
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>

Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C


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