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Message-Id: <20190127.104112.895755013017380628.davem@davemloft.net>
To:     atsushi.nemoto@sord.co.jp
Cc:     thor.thayer@linux.intel.com, netdev@vger.kernel.org,
        dalon.westergreen@linux.intel.com, tomonori.sakita@sord.co.jp
Subject: Re: [PATCH v2] net: altera_tse: fix msgdma_tx_completion on
 non-zero fill_level case
From:   David Miller <davem@davemloft.net>
In-Reply-To: <20190125.110222.956948485194493083.atsushi.nemoto@sord.co.jp>
References: <20190125.110222.956948485194493083.atsushi.nemoto@sord.co.jp>
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From: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
Date: Fri, 25 Jan 2019 11:02:22 +0900

> From: Tomonori Sakita <tomonori.sakita@sord.co.jp>
> 
> If fill_level was not zero and status was not BUSY,
> result of "tx_prod - tx_cons - inuse" might be zero.
> Subtracting 1 unconditionally results invalid negative return value
> on this case.
> Make sure not to return an negative value.
> 
> Signed-off-by: Tomonori Sakita <tomonori.sakita@sord.co.jp>
> Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp>
> Reviewed-by: Dalon L Westergreen <dalon.westergreen@linux.intel.com>
> ---
> Changes in v2:
>   Use max_t instead of just removing the "- 1".

Applied.