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From:   Chris Clayton <chris2553@googlemail.com>
Reply-To: chris2553@googlemail.com
Subject: Re: [PATCH] misc: rtsx: do not setting OC_POWER_DOWN reg in
 rtsx_pci_init_ocp()
To:     ricky_wu@realtek.com, arnd@arndb.de, gregkh@linuxfoundation.org,
        bhelgaas@google.com, vaibhavgupta40@gmail.com,
        rui_feng@realsil.com.cn, kdlnx@doth.eu,
        linux-kernel@vger.kernel.org
References: <20200824030006.30033-1-ricky_wu@realtek.com>
Message-ID: <c06d7691-01ab-303c-e687-dd8c51a8a9c5@gmail.com>
Date:   Sun, 13 Sep 2020 09:40:56 +0100
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Hi Greg and Arnd,

On 24/08/2020 04:00, ricky_wu@realtek.com wrote:
> From: Ricky Wu <ricky_wu@realtek.com>
> 
> this power saving action in rtsx_pci_init_ocp() cause INTEL-NUC6 platform
> missing card reader
> 

In his changelog above, Ricky didn't mention that this patch fixes a regression that was introduced (in 5.1) by commit
bede03a579b3.

The patch that I posted to LKML contained the appropriate Fixes, etc tags. After discussion, the patch was changed to
remove the code that effectively disables the RTS5229 cardreader on (at least some) Intel NUC boxes. I prepared the
patch that Ricky submitted but he didn't include my Signed-off-by or the Fixes tag. I think the following needs to be
added to the changelog.

Fixes: bede03a579b3 ("misc: rtsx: Enable OCP for rts522a rts524a rts525a rts5260")
Link: https://marc.info/?l=linux-kernel&m=159105912832257
Link: https://bugzilla.kernel.org/show_bug.cgi?id=204003
Signed-off-by: Chris Clayton <chris2553@googlemail.com>

bede03a579b3 introduced a bug which leaves the rts5229 PCI Express card reader on the Intel NUC6CAYH box.

My main point, however, is that the patch is also needed in the 5.4 (longterm) and 5.8 (stable) series kernels.

Thanks.


> Signed-off-by: Ricky Wu <ricky_wu@realtek.com>
> ---
>  drivers/misc/cardreader/rtsx_pcr.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/misc/cardreader/rtsx_pcr.c b/drivers/misc/cardreader/rtsx_pcr.c
> index 37ccc67f4914..3a4a7b0cc098 100644
> --- a/drivers/misc/cardreader/rtsx_pcr.c
> +++ b/drivers/misc/cardreader/rtsx_pcr.c
> @@ -1155,10 +1155,6 @@ void rtsx_pci_init_ocp(struct rtsx_pcr *pcr)
>  			rtsx_pci_write_register(pcr, REG_OCPGLITCH,
>  				SD_OCP_GLITCH_MASK, pcr->hw_param.ocp_glitch);
>  			rtsx_pci_enable_ocp(pcr);
> -		} else {
> -			/* OC power down */
> -			rtsx_pci_write_register(pcr, FPDCTL, OC_POWER_DOWN,
> -				OC_POWER_DOWN);
>  		}
>  	}
>  }
>