Re: [PATCH v1 net] net: mscc: ocelot: remove buggy and useless write to ANA_PFC_PFC_CFG

From: Vladimir Oltean
Date: Thu Sep 16 2021 - 07:49:25 EST


On Wed, Sep 15, 2021 at 06:09:37PM -0700, Colin Foster wrote:
> A useless write to ANA_PFC_PFC_CFG was left in while refactoring ocelot to
> phylink. Since priority flow control is disabled, writing the speed has no
> effect.
>
> Further, it was using ethtool.h SPEED_ instead of OCELOT_SPEED_ macros,
> which are incorrectly offset for GENMASK.
>
> Lastly, for priority flow control to properly function, some scenarios
> would rely on the rate adaptation from the PCS while the MAC speed would
> be fixed. So it isn't used, and even if it was, neither "speed" nor
> "mac_speed" are necessarily the correct values to be used.
>
> Fixes: e6e12df625f2 ("net: mscc: ocelot: convert to phylink")
> Signed-off-by: Colin Foster <colin.foster@xxxxxxxxxxxxxxxx>
> ---
> drivers/net/ethernet/mscc/ocelot.c | 4 ----
> 1 file changed, 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
> index c581b955efb3..08be0440af28 100644
> --- a/drivers/net/ethernet/mscc/ocelot.c
> +++ b/drivers/net/ethernet/mscc/ocelot.c
> @@ -569,10 +569,6 @@ void ocelot_phylink_mac_link_up(struct ocelot *ocelot, int port,
> ocelot_port_writel(ocelot_port, DEV_CLOCK_CFG_LINK_SPEED(speed),
> DEV_CLOCK_CFG);
>
> - /* No PFC */
> - ocelot_write_gix(ocelot, ANA_PFC_PFC_CFG_FC_LINK_SPEED(speed),
> - ANA_PFC_PFC_CFG, port);
> -

This will conflict with the other patch.... why didn't you send both as
part of a series? By not doing that, you are telling patchwork to
build-test them in parallel, which of course does not work:
https://patchwork.kernel.org/project/netdevbpf/patch/20210916012341.518512-1-colin.foster@xxxxxxxxxxxxxxxx/

Also, why didn't you bump the version counter of the patch, and we're
still at v1 despite the earlier attempt?

git format-patch -2 --cover-letter --subject-prefix="PATCH v3 net" -o /opt/patches/linux/ocelot-phylink-fixes/v3/
./scripts/get_maintainer.pl /opt/patches/linux/ocelot-phylink-fixes/v3/*.patch
./scripts/checkpatch.pl --strict /opt/patches/linux/ocelot-phylink-fixes/v3/*.patch
# Go through patches, write change log compared to v2 using vimdiff, meld, git range-diff, whatever
# Write cover letter summarizing what changes and why. If fixing bugs explain the impact.
git send-email \
--to='netdev@xxxxxxxxxxxxxxx' \
--to='linux-kernel@xxxxxxxxxxxxxxx' \
--cc='Vladimir Oltean <vladimir.oltean@xxxxxxx>' \
--cc='Claudiu Manoil <claudiu.manoil@xxxxxxx>' \
--cc='Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>' \
--cc='UNGLinuxDriver@xxxxxxxxxxxxx' \
--cc='"David S. Miller" <davem@xxxxxxxxxxxxx>' \
--cc='Jakub Kicinski <kuba@xxxxxxxxxx>' \
/opt/patches/linux/ocelot-phylink-fixes/v3/*.patch

Reviewed-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>

Please keep this tag but resend a new version. You can download the patch with the review tags automatically using:
git b4 20210916010938.517698-1-colin.foster@xxxxxxxxxxxxxxxx
git b4 20210916012341.518512-1-colin.foster@xxxxxxxxxxxxxxxx

where "git b4" is an alias configured like this in ~/.gitconfig:

[b4]
midmask = https://lore.kernel.org/r/%s
[alias]
b4 = "!f() { b4 am -t -o - $@ | git am -3; }; f"