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Miller" , Jakub Kicinski , Palmer Dabbelt , Paul Walmsley , Drew Fustini , Emil Renner Berthing , Jon Hunter , Will Deacon References: <20210614022504.24458-1-mcroce@linux.microsoft.com> <871r71azjw.wl-maz@kernel.org> <202417ef-f8ae-895d-4d07-1f9f3d89b4a4@gmail.com> <87o8a49idp.wl-maz@kernel.org> From: Eric Dumazet Message-ID: Date: Thu, 12 Aug 2021 10:48:03 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <87o8a49idp.wl-maz@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 8/11/21 4:16 PM, Marc Zyngier wrote: > On Wed, 11 Aug 2021 13:53:59 +0100, > Eric Dumazet wrote: > >> Are you sure you do not need to adjust stmmac_set_bfsize(), >> stmmac_rx_buf1_len() and stmmac_rx_buf2_len() ? >> >> Presumably DEFAULT_BUFSIZE also want to be increased by NET_SKB_PAD >> >> Patch for stmmac_rx_buf1_len() : >> >> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c >> index 7b8404a21544cf29668e8a14240c3971e6bce0c3..041a74e7efca3436bfe3e17f972dd156173957a9 100644 >> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c >> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c >> @@ -4508,12 +4508,12 @@ static unsigned int stmmac_rx_buf1_len(struct stmmac_priv *priv, >> >> /* First descriptor, not last descriptor and not split header */ >> if (status & rx_not_ls) >> - return priv->dma_buf_sz; >> + return priv->dma_buf_sz - NET_SKB_PAD - NET_IP_ALIGN; >> >> plen = stmmac_get_rx_frame_len(priv, p, coe); >> >> /* First descriptor and last descriptor and not split header */ >> - return min_t(unsigned int, priv->dma_buf_sz, plen); >> + return min_t(unsigned int, priv->dma_buf_sz - NET_SKB_PAD - NET_IP_ALIGN, plen); >> } >> >> static unsigned int stmmac_rx_buf2_len(struct stmmac_priv *priv, > > Feels like a major deficiency of the original patch. Happy to test a > more complete patch if/when you have one. I wont have time in the immediate future. Matteo, if you do not work on a fix, I suggest we revert a955318fe67ec0d962760b5ee58e74bffaf649b8 stmmac: align RX buffers before a more polished version can be submitted.