From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48E38C41513 for ; Tue, 1 Aug 2023 14:11:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233677AbjHAOLR (ORCPT ); Tue, 1 Aug 2023 10:11:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231359AbjHAOLO (ORCPT ); Tue, 1 Aug 2023 10:11:14 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76B7918D; Tue, 1 Aug 2023 07:11:13 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0CA6C615A5; Tue, 1 Aug 2023 14:11:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9157AC433C8; Tue, 1 Aug 2023 14:11:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690899072; bh=Va+3BpK80OaOladXcfkefzEKQDa7NapSdHQhUuxB8IY=; h=Subject:From:In-Reply-To:References:To:Cc:Date:From; b=aKmKRyrrWqC3G193vS32cSDtgtS7OvNINFtMQGWdR0HnYrOsPwzriMcAg0XAN+QZ7 xqLSODj1BmwE1D031eb+P6ERJiuT74u8o/1oo7pVV6HDL+8OL5OJGZS59YUesflW3j 5NeMVDSrpKfPlw3unLZH+SXEIAEYFtfOh/lEjCbCgNcbL67i+wXNQsqE3Kqnw0pG7k sR0rL2wb1o7biLoYIbHngkU4IUFNXzn7C9uixH1maqMqWUl9gQMYGp/ghy0K/AlUmC mT9yF49BOgNj1FgJSxQjVG+XKD7RIPZHZFpeH6JH2LevFQxr40wo7K/TMswKpl7Pnv /7G+EHFhRa6UQ== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [PATCH] wifi: rtw88: sdio: Honor the host max_req_size in the RX path From: Kalle Valo In-Reply-To: <20230709195712.603200-1-martin.blumenstingl@googlemail.com> References: <20230709195712.603200-1-martin.blumenstingl@googlemail.com> To: Martin Blumenstingl Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, jernej.skrabec@gmail.com, pkshih@realtek.com, ulf.hansson@linaro.org, tony0620emma@gmail.com, Martin Blumenstingl , "Lukas F . Hartmann" User-Agent: pwcli/0.1.1-git (https://github.com/kvalo/pwcli/) Python/3.11.2 Message-ID: <169089906853.212423.17095176293160428610.kvalo@kernel.org> Date: Tue, 1 Aug 2023 14:11:10 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Martin Blumenstingl wrote: > Lukas reports skb_over_panic errors on his Banana Pi BPI-CM4 which comes > with an Amlogic A311D (G12B) SoC and a RTL8822CS SDIO wifi/Bluetooth > combo card. The error he observed is identical to what has been fixed > in commit e967229ead0e ("wifi: rtw88: sdio: Check the HISR RX_REQUEST > bit in rtw_sdio_rx_isr()") but that commit didn't fix Lukas' problem. > > Lukas found that disabling or limiting RX aggregation fix the problem > for him. In the following discussion a few key topics have been > discussed which have an impact on this problem: > - The Amlogic A311D (G12B) SoC has a hardware bug in the SDIO controller > which prevents DMA transfers. Instead all transfers need to go through > the controller SRAM which limits transfers to 1536 bytes > - rtw88 chips don't split incoming (RX) packets, so if a big packet is > received this is forwarded to the host in it's original form > - rtw88 chips can do RX aggregation, meaning more multiple incoming > packets can be pulled by the host from the card with one MMC/SDIO > transfer. This Depends on settings in the REG_RXDMA_AGG_PG_TH > register (BIT_RXDMA_AGG_PG_TH limits the number of packets that will > be aggregated, BIT_DMA_AGG_TO_V1 configures a timeout for aggregation > and BIT_EN_PRE_CALC makes the chip honor the limits more effectively) > > Use multiple consecutive reads in rtw_sdio_read_port() to limit the > number of bytes which are copied by the host from the card in one > MMC/SDIO transfer. This allows receiving a buffer that's larger than > the hosts max_req_size (number of bytes which can be transferred in > one MMC/SDIO transfer). As a result of this the skb_over_panic error > is gone as the rtw88 driver is now able to receive more than 1536 bytes > from the card (either because the incoming packet is larger than that > or because multiple packets have been aggregated). > > Fixes: 65371a3f14e7 ("wifi: rtw88: sdio: Add HCI implementation for SDIO based chipsets") > Reported-by: Lukas F. Hartmann > Closes: https://lore.kernel.org/linux-wireless/CAFBinCBaXtebixKbjkWKW_WXc5k=NdGNaGUjVE8NCPNxOhsb2g@mail.gmail.com/ > Suggested-by: Ping-Ke Shih > Signed-off-by: Martin Blumenstingl > Reviewed-by: Ping-Ke Shih Ping, should I take or drop the patch? It wasn't quite clear for me. -- https://patchwork.kernel.org/project/linux-wireless/patch/20230709195712.603200-1-martin.blumenstingl@googlemail.com/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches