Re: [PATCH 4.1 11/56] mvneta: add forgotten initialization of autonegotiation bits

[Stas Sergeev <stsp@list.ru>]

08.07.2015 10:35, Greg Kroah-Hartman пишет:
> 4.1-stable review patch.  If anyone has any objections, please let me know.
>
> ------------------
>
> From: Stas Sergeev <stsp@list.ru>
>
> [ Upstream commit 538761b794c1542f1c6e31eadd9d7aae118889f7 ]
>
> The commit 898b2970e2c9 ("mvneta: implement SGMII-based in-band link state
> signaling")
> changed mvneta_adjust_link() so that it does not clear the auto-negotiation
> bits in MVNETA_GMAC_AUTONEG_CONFIG register. This was necessary for
> auto-negotiation mode to work.
> Unfortunately I haven't checked if these bits are ever initialized.
> It appears they are not.
> This patch adds the missing initialization of the auto-negotiation bits
> in the MVNETA_GMAC_AUTONEG_CONFIG register.
> It fixes the following regression:
> https://www.mail-archive.com/netdev@vger.kernel.org/msg67928.html
>
> Since the patch was tested to fix a regression, it should be applied to
> stable tree.
>
> Tested-by: Arnaud Ebalard <arno@natisbad.org>
>
> CC: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> CC: Florian Fainelli <f.fainelli@gmail.com>
> CC: netdev@vger.kernel.org
> CC: linux-kernel@vger.kernel.org
> CC: stable@vger.kernel.org
>
> Signed-off-by: Stas Sergeev <stsp@users.sourceforge.net>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>   drivers/net/ethernet/marvell/mvneta.c |    6 ++++++
>   1 file changed, 6 insertions(+)
>
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -1013,6 +1013,12 @@ static void mvneta_defaults_set(struct m
>   		val = mvreg_read(pp, MVNETA_GMAC_CLOCK_DIVIDER);
>   		val |= MVNETA_GMAC_1MS_CLOCK_ENABLE;
>   		mvreg_write(pp, MVNETA_GMAC_CLOCK_DIVIDER, val);
> +	} else {
> +		val = mvreg_read(pp, MVNETA_GMAC_AUTONEG_CONFIG);
> +		val &= ~(MVNETA_GMAC_INBAND_AN_ENABLE |
> +		       MVNETA_GMAC_AN_SPEED_EN |
> +		       MVNETA_GMAC_AN_DUPLEX_EN);
> +		mvreg_write(pp, MVNETA_GMAC_AUTONEG_CONFIG, val);
>   	}
>   
>   	mvneta_set_ucast_table(pp, -1);
Hi Greg.

Another problem was reported:
https://lkml.org/lkml/2015/7/8/865

So, while the above patch is correct and fixes what
it should, the original patch has more problems to deal
with. Maybe for stable it would be better to just revert
the whole thing?
I guess for stable I'll be posting the reverts instead of
the above fix.