From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 81AAF11C94 for ; Mon, 28 Aug 2023 10:31:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 017EDC433C9; Mon, 28 Aug 2023 10:31:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693218673; bh=eEszNnF9DLOiZD1hOEfoxORMXqIYdvNn2hHnbx30s6U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hCiywjbkdoHEg/EOCAIJLY0jzOxbeQ+ufq582XDP36dimEkcfZZj+Zm0PHC9p+JeC tnehLCTaOcbXyRYwWN/sZOLouy9eOv2S523aJHmGdWPxasibTgHTzG3S0ufAcjKbnT zrc9Op6HOLJbeAv2WlcwVUPvC5XapiKvQ93a6+ts= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Przemek Kitszel , Jesse Brandeburg , Leon Romanovsky , Tony Nguyen , Sasha Levin , Pucha Himasekhar Reddy Subject: [PATCH 6.1 042/122] ice: fix receive buffer size miscalculation Date: Mon, 28 Aug 2023 12:12:37 +0200 Message-ID: <20230828101157.803913979@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101156.480754469@linuxfoundation.org> References: <20230828101156.480754469@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jesse Brandeburg [ Upstream commit 10083aef784031fa9f06c19a1b182e6fad5338d9 ] The driver is misconfiguring the hardware for some values of MTU such that it could use multiple descriptors to receive a packet when it could have simply used one. Change the driver to use a round-up instead of the result of a shift, as the shift can truncate the lower bits of the size, and result in the problem noted above. It also aligns this driver with similar code in i40e. The insidiousness of this problem is that everything works with the wrong size, it's just not working as well as it could, as some MTU sizes end up using two or more descriptors, and there is no way to tell that is happening without looking at ice_trace or a bus analyzer. Fixes: efc2214b6047 ("ice: Add support for XDP") Reviewed-by: Przemek Kitszel Signed-off-by: Jesse Brandeburg Reviewed-by: Leon Romanovsky Tested-by: Pucha Himasekhar Reddy (A Contingent worker at Intel) Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/ice/ice_base.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/ice/ice_base.c b/drivers/net/ethernet/intel/ice/ice_base.c index e864634d66bc6..818eca6aa4a41 100644 --- a/drivers/net/ethernet/intel/ice/ice_base.c +++ b/drivers/net/ethernet/intel/ice/ice_base.c @@ -396,7 +396,8 @@ static int ice_setup_rx_ctx(struct ice_rx_ring *ring) /* Receive Packet Data Buffer Size. * The Packet Data Buffer Size is defined in 128 byte units. */ - rlan_ctx.dbuf = ring->rx_buf_len >> ICE_RLAN_CTX_DBUF_S; + rlan_ctx.dbuf = DIV_ROUND_UP(ring->rx_buf_len, + BIT_ULL(ICE_RLAN_CTX_DBUF_S)); /* use 32 byte descriptors */ rlan_ctx.dsize = 1; -- 2.40.1