linux-kernel - Re: [PATCH] i2c: tegra-bpmp: ignore DMA safe buffer flag

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Message-ID: <16a0be21-2cbe-dd0e-aed7-b84f6abcacac@codethink.co.uk>
Date:   Mon, 11 Jan 2021 15:04:50 +0000
From:   Ben Dooks <ben.dooks@...ethink.co.uk>
To:     Mikko Perttunen <mperttunen@...dia.com>, thierry.reding@...il.com,
        jonathanh@...dia.com
Cc:     talho@...dia.com, linux-i2c@...r.kernel.org,
        linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org,
        Muhammed Fazal <mfazale@...dia.com>, stable@...r.kernel.org
Subject: Re: [PATCH] i2c: tegra-bpmp: ignore DMA safe buffer flag

On 11/01/2021 14:27, Mikko Perttunen wrote:
> From: Muhammed Fazal <mfazale@...dia.com>
> 
> Ignore I2C_M_DMA_SAFE flag as it does not make a difference
> for bpmp-i2c, but causes -EINVAL to be returned for valid
> transactions.
> 
> Signed-off-by: Muhammed Fazal <mfazale@...dia.com>
> Cc: stable@...r.kernel.org # v4.19+
> Signed-off-by: Mikko Perttunen <mperttunen@...dia.com>
> ---
> This fixes failures seen with PMIC probing tools on
> Tegra186+ boards.
> 
>   drivers/i2c/busses/i2c-tegra-bpmp.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-tegra-bpmp.c b/drivers/i2c/busses/i2c-tegra-bpmp.c
> index ec7a7e917edd..998d4b21fb59 100644
> --- a/drivers/i2c/busses/i2c-tegra-bpmp.c
> +++ b/drivers/i2c/busses/i2c-tegra-bpmp.c
> @@ -80,6 +80,9 @@ static int tegra_bpmp_xlate_flags(u16 flags, u16 *out)
>   		flags &= ~I2C_M_RECV_LEN;
>   	}
>   
> +	if (flags & I2C_M_DMA_SAFE)
> +		flags &= ~I2C_M_DMA_SAFE;
> +

Just a comment, you can do without the test here.
Just doing this would have been fine:

	flags &= ~I2C_M_DMA_SAFE;



-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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