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Date:   Wed, 28 Apr 2021 07:59:28 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Timo Sigurdsson <public_timo.s@silentcreek.de>
Cc:     axboe@kernel.dk, mripard@kernel.org, wens@csie.org,
        jernej.skrabec@siol.net, linux-ide@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev,
        linux-kernel@vger.kernel.org, oliver@schinagl.nl,
        stable@vger.kernel.org
Subject: Re: [PATCH] ata: ahci_sunxi: Disable DIPM
Message-ID: <YIj5wKTdOVWLdD2d@kroah.com>
References: <20210427230537.21423-1-public_timo.s@silentcreek.de>
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In-Reply-To: <20210427230537.21423-1-public_timo.s@silentcreek.de>
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On Wed, Apr 28, 2021 at 01:05:37AM +0200, Timo Sigurdsson wrote:
> DIPM is unsupported or broken on sunxi. Trying to enable the power
> management policy med_power_with_dipm on an Allwinner A20 SoC based board
> leads to immediate I/O errors and the attached SATA disk disappears from
> the /dev filesystem. A reset (power cycle) is required to make the SATA
> controller or disk work again. The A10 and A20 SoC data sheets and manuals
> don't mention DIPM at all [1], so it's fair to assume that it's simply not
> supported. But even if it were, it should be considered broken and best be
> disabled in the ahci_sunxi driver.
> 
> Fixes: c5754b5220f0 ("ARM: sunxi: Add support for Allwinner SUNXi SoCs sata to ahci_platform")
> 
> [1] https://github.com/allwinner-zh/documents/tree/master/
> 
> Signed-off-by: Timo Sigurdsson <public_timo.s@silentcreek.de>
> Tested-by: Timo Sigurdsson <public_timo.s@silentcreek.de>
> ---
>  drivers/ata/ahci_sunxi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/ata/ahci_sunxi.c b/drivers/ata/ahci_sunxi.c
> index cb69b737cb49..56b695136977 100644
> --- a/drivers/ata/ahci_sunxi.c
> +++ b/drivers/ata/ahci_sunxi.c
> @@ -200,7 +200,7 @@ static void ahci_sunxi_start_engine(struct ata_port *ap)
>  }
>  
>  static const struct ata_port_info ahci_sunxi_port_info = {
> -	.flags		= AHCI_FLAG_COMMON | ATA_FLAG_NCQ,
> +	.flags		= AHCI_FLAG_COMMON | ATA_FLAG_NCQ | ATA_FLAG_NO_DIPM,
>  	.pio_mask	= ATA_PIO4,
>  	.udma_mask	= ATA_UDMA6,
>  	.port_ops	= &ahci_platform_ops,
> -- 
> 2.26.2
> 
<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>