linux-kernel - Re: [PATCH 0/2] firmware: cs_dsp: Remove usage of GFP

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Message-ID: <0e9c1cca-592f-4983-93f4-ab2f76a3c97e@opensource.cirrus.com>
Date: Tue, 11 Feb 2025 17:21:08 +0000
From: Richard Fitzgerald <rf@...nsource.cirrus.com>
To: Thomas Weißschuh <thomas.weissschuh@...utronix.de>,
        "Simon Trimmer" <simont@...nsource.cirrus.com>,
        Charles Keepax
	<ckeepax@...nsource.cirrus.com>,
        Mark Brown <broonie@...nel.org>
CC: <patches@...nsource.cirrus.com>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/2] firmware: cs_dsp: Remove usage of GFP_DMA

On 11/02/2025 5:03 pm, Thomas Weißschuh wrote:
> Also drop the bounce buffer in cs_dsp_coeff_write_ctrl_raw().
> 
> The bounce buffer in cs_dsp_coeff_write_ctrl_raw() could theoretically
> also be removed. That would be a functional change as the output may be
> modified in error cases.
> As I don't know the driver very well I left that part out.
> 
> Not tested on real hardware.
> This came up while porting kunit to mips64.
> Apparently GFP_DMA does not work there, but IMO the usage of GFP_DMA by
> cs_dsp is unnecessary in the first place.
> 

You're sure that all I2C and SPI bus controllers now handle non-DMA-safe
buffers correctly?

> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
> ---
> Thomas Weißschuh (2):
>        firmware: cs_dsp: Remove usage of GFP_DMA
>        firmware: cs_dsp: Remove bounce buffer in cs_dsp_coeff_write_ctrl_raw()
> 
>   drivers/firmware/cirrus/cs_dsp.c | 15 +++------------
>   1 file changed, 3 insertions(+), 12 deletions(-)
> ---
> base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
> change-id: 20250211-cs_dsp-gfp_dma-0581bdd09dd5
> 
> Best regards,