linux-kernel - Re: [PATCH v3 2/2] dmaengine: dw-axi-dmac: add reset control support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <9f7514c69d11a0377283fe52fa6e7558b75c7ad3.camel@pengutronix.de>
Date: Fri, 17 Oct 2025 11:47:50 +0200
From: Philipp Zabel <p.zabel@...gutronix.de>
To: Artem Shimko <a.shimko.dev@...il.com>, Eugeniy Paltsev
	 <Eugeniy.Paltsev@...opsys.com>, Vinod Koul <vkoul@...nel.org>
Cc: dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/2] dmaengine: dw-axi-dmac: add reset control support

On Do, 2025-10-16 at 18:46 +0300, Artem Shimko wrote:
> Add proper reset control handling to the AXI DMA driver to ensure
> reliable initialization and power management. The driver now manages
> resets during probe, remove, and system suspend/resume operations.
> 
> The implementation stores reset control in the chip structure and adds
> reset assert/deassert calls at the appropriate points: resets are
> deasserted during probe after clock acquisition, asserted during remove
> and error cleanup, and properly managed during suspend/resume cycles.
> Additionally, proper error handling is implemented for reset control
> operations to ensure robust behavior.
> 
> This ensures the controller is properly reset during power transitions
> and prevents potential issues with incomplete initialization.
> 
> Signed-off-by: Artem Shimko <a.shimko.dev@...il.com>
> ---
>  .../dma/dw-axi-dmac/dw-axi-dmac-platform.c    | 42 ++++++++++++-------
>  drivers/dma/dw-axi-dmac/dw-axi-dmac.h         |  1 +
>  2 files changed, 27 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> index 8b7cf3baf5d3..ac23e1a5e218 100644
> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> @@ -1321,6 +1321,8 @@ static int axi_dma_suspend(struct device *dev)
>  	axi_dma_irq_disable(chip);
>  	axi_dma_disable(chip);
>  
> +	reset_control_assert(chip->resets);
> +
>  	clk_disable_unprepare(chip->core_clk);
>  	clk_disable_unprepare(chip->cfgr_clk);
>  
> @@ -1340,6 +1342,8 @@ static int axi_dma_resume(struct device *dev)
>  	if (ret < 0)
>  		return ret;
>  
> +	reset_control_deassert(chip->resets);
> +

Missing error handling, or at least inconsistent with the deassert
turing dw_probe().

regards
Philipp