Date:   Mon, 13 Feb 2023 14:29:40 +0300
From:   Dan Carpenter <error27@gmail.com>
To:     Steen Hegelund <steen.hegelund@microchip.com>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, UNGLinuxDriver@microchip.com,
        Randy Dunlap <rdunlap@infradead.org>,
        Casper Andersson <casper.casan@gmail.com>,
        Russell King <rmk+kernel@armlinux.org.uk>,
        Wan Jiabing <wanjiabing@vivo.com>,
        Nathan Huckleberry <nhuck@google.com>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        Daniel Machon <daniel.machon@microchip.com>,
        Horatiu Vultur <horatiu.vultur@microchip.com>,
        Lars Povlsen <lars.povlsen@microchip.com>,
        Michael Walle <michael@walle.cc>
Subject: Re: [PATCH net-next 02/10] net: microchip: sparx5: Clear rule
 counter even if lookup is disabled
Message-ID: <Y+ofJK2psEnj9QNh@kadam>
References: <20230213092426.1331379-1-steen.hegelund@microchip.com>
 <20230213092426.1331379-3-steen.hegelund@microchip.com>
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In-Reply-To: <20230213092426.1331379-3-steen.hegelund@microchip.com>
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On Mon, Feb 13, 2023 at 10:24:18AM +0100, Steen Hegelund wrote:
> The rule counter must be cleared when creating a new rule, even if the VCAP
> lookup is currently disabled.
> 
> Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>

Is this a bugfix?  If so what are the user visible effects of this bug
and please add a Fixes tag.  If not then could you explain more what
this patch is for?

> ---
>  drivers/net/ethernet/microchip/vcap/vcap_api.c       | 7 +++++--
>  drivers/net/ethernet/microchip/vcap/vcap_api_kunit.c | 4 ++--
>  2 files changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api.c b/drivers/net/ethernet/microchip/vcap/vcap_api.c
> index 6307d59f23da..68e04d47f6fd 100644
> --- a/drivers/net/ethernet/microchip/vcap/vcap_api.c
> +++ b/drivers/net/ethernet/microchip/vcap/vcap_api.c
> @@ -2246,6 +2246,11 @@ int vcap_add_rule(struct vcap_rule *rule)
>  	if (move.count > 0)
>  		vcap_move_rules(ri, &move);
>  
> +	/* Set the counter to zero */
> +	ret = vcap_write_counter(ri, &ctr);
> +	if (ret)
> +		goto out;
> +
>  	if (ri->state == VCAP_RS_DISABLED) {
>  		/* Erase the rule area */
>  		ri->vctrl->ops->init(ri->ndev, ri->admin, ri->addr, ri->size);
> @@ -2264,8 +2269,6 @@ int vcap_add_rule(struct vcap_rule *rule)
>  		pr_err("%s:%d: rule write error: %d\n", __func__, __LINE__, ret);
>  		goto out;
>  	}
> -	/* Set the counter to zero */
> -	ret = vcap_write_counter(ri, &ctr);
>  out:
>  	mutex_unlock(&ri->admin->lock);
>  	return ret;
> diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api_kunit.c b/drivers/net/ethernet/microchip/vcap/vcap_api_kunit.c
> index b2753aac8ad2..0a1d4d740567 100644
> --- a/drivers/net/ethernet/microchip/vcap/vcap_api_kunit.c
> +++ b/drivers/net/ethernet/microchip/vcap/vcap_api_kunit.c
> @@ -1337,8 +1337,8 @@ static void vcap_api_encode_rule_test(struct kunit *test)
>  	u32 port_mask_rng_mask = 0x0f;
>  	u32 igr_port_mask_value = 0xffabcd01;
>  	u32 igr_port_mask_mask = ~0;
> -	/* counter is written as the last operation */
> -	u32 expwriteaddr[] = {792, 793, 794, 795, 796, 797, 792};
> +	/* counter is written as the first operation */
> +	u32 expwriteaddr[] = {792, 792, 793, 794, 795, 796, 797};

So this moves 792 from the last to the first.  I would have expected
that that would mean that we had to do something like this as well:

diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api_kunit.c b/drivers/net/ethernet/microchip/vcap/vcap_api_kunit.c
index b2753aac8ad2..4d36fad0acab 100644
--- a/drivers/net/ethernet/microchip/vcap/vcap_api_kunit.c
+++ b/drivers/net/ethernet/microchip/vcap/vcap_api_kunit.c
@@ -1400,7 +1400,7 @@ static void vcap_api_encode_rule_test(struct kunit *test)
 	/* Add rule with write callback */
 	ret = vcap_add_rule(rule);
 	KUNIT_EXPECT_EQ(test, 0, ret);
-	KUNIT_EXPECT_EQ(test, 792, is2_admin.last_used_addr);
+	KUNIT_EXPECT_EQ(test, 797, is2_admin.last_used_addr);
 	for (idx = 0; idx < ARRAY_SIZE(expwriteaddr); ++idx)
 		KUNIT_EXPECT_EQ(test, expwriteaddr[idx], test_updateaddr[idx]);
 

But I couldn't really figure out how the .last_used_addr stuff works.
And presumably fixing this unit test is the point of the patch...

regards,
dan carpenter