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 CA8836FAF for ; Mon, 28 Aug 2023 10:48:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D045C433C7; Mon, 28 Aug 2023 10:48:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693219686; bh=w//VUv9aUNd4f+mZDg0jEffixjvyG7prfxEB1rHz6fo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fF+4qdBN7LTlP5VEeA6NG0VTkCB2nm8UDqJF3L8aRUs86n1A92P2o22A4vQCRU8mw Ibd4YT6kEU1em8j3TEMHG/gFezzwqCfgAxV3Lbsq71aRE92bB9UWxOftmP0ddlhUz9 DAa1Bf7f5A+k6oRUoUoRK+AmRr4EwjQMTBxZdpDk= 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 5.10 34/84] ice: fix receive buffer size miscalculation Date: Mon, 28 Aug 2023 12:13:51 +0200 Message-ID: <20230828101150.415479056@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101149.146126827@linuxfoundation.org> References: <20230828101149.146126827@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 5.10-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 1929847b8c404..59df4c9bd8f90 100644 --- a/drivers/net/ethernet/intel/ice/ice_base.c +++ b/drivers/net/ethernet/intel/ice/ice_base.c @@ -353,7 +353,8 @@ int ice_setup_rx_ctx(struct ice_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