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 5412EC64EC4 for ; Fri, 10 Mar 2023 14:03:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231579AbjCJODI (ORCPT ); Fri, 10 Mar 2023 09:03:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231580AbjCJOCv (ORCPT ); Fri, 10 Mar 2023 09:02:51 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06793117594 for ; Fri, 10 Mar 2023 06:02:49 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 5037FCE28F7 for ; Fri, 10 Mar 2023 14:02:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E408C433EF; Fri, 10 Mar 2023 14:02:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678456966; bh=tf7vzkLXAEOY4mHOq0SXQt+xIicFBgpYPcTbupABLN4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=odNOxpVV8XJAj2NUjIvxfWATprM55goBdLkYwFHuj3/8ByDU4pURczyzps7kn+62K rPwMnxAmG/7dfj/VaowuV7mBR0uXS1XWJG/NAivAklTNc1uzowCKnM6WZ59YYL2R8j cl0WJyGtait0AUCSY7P+MUEoPvp2q1h6EKiXKfMA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Richard Fitzgerald , Pierre-Louis Bossart , Vinod Koul , Sasha Levin Subject: [PATCH 6.2 187/211] soundwire: cadence: Drain the RX FIFO after an IO timeout Date: Fri, 10 Mar 2023 14:39:27 +0100 Message-Id: <20230310133724.529460030@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133718.689332661@linuxfoundation.org> References: <20230310133718.689332661@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Richard Fitzgerald [ Upstream commit 0603a47bd3a8f439d7844b841eee1819353063e0 ] If wait_for_completion_timeout() times-out in _cdns_xfer_msg() it is possible that something could have been written to the RX FIFO. In this case, we should drain the RX FIFO so that anything in it doesn't carry over and mess up the next transfer. Obviously, if we got to this state something went wrong, and we don't really know the state of everything. The cleanup in this situation cannot be bullet-proof but we should attempt to avoid breaking future transaction, if only to reduce the amount of error noise when debugging the failure from a kernel log. Note that this patch only implements the draining for blocking (non-deferred) transfers. The deferred API doesn't have any proper handling of error conditions and would need some re-design before implementing cleanup. That is a task for a separate patch... Signed-off-by: Richard Fitzgerald Reviewed-by: Pierre-Louis Bossart Link: https://lore.kernel.org/r/20221202161812.4186897-4-rf@opensource.cirrus.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/soundwire/cadence_master.c | 50 ++++++++++++++++-------------- 1 file changed, 27 insertions(+), 23 deletions(-) diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index a6635f7f350ef..5213873221458 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -555,6 +555,29 @@ cdns_fill_msg_resp(struct sdw_cdns *cdns, return SDW_CMD_OK; } +static void cdns_read_response(struct sdw_cdns *cdns) +{ + u32 num_resp, cmd_base; + int i; + + /* RX_FIFO_AVAIL can be 2 entries more than the FIFO size */ + BUILD_BUG_ON(ARRAY_SIZE(cdns->response_buf) < CDNS_MCP_CMD_LEN + 2); + + num_resp = cdns_readl(cdns, CDNS_MCP_FIFOSTAT); + num_resp &= CDNS_MCP_RX_FIFO_AVAIL; + if (num_resp > ARRAY_SIZE(cdns->response_buf)) { + dev_warn(cdns->dev, "RX AVAIL %d too long\n", num_resp); + num_resp = ARRAY_SIZE(cdns->response_buf); + } + + cmd_base = CDNS_MCP_CMD_BASE; + + for (i = 0; i < num_resp; i++) { + cdns->response_buf[i] = cdns_readl(cdns, cmd_base); + cmd_base += CDNS_MCP_CMD_WORD_LEN; + } +} + static enum sdw_command_response _cdns_xfer_msg(struct sdw_cdns *cdns, struct sdw_msg *msg, int cmd, int offset, int count, bool defer) @@ -596,6 +619,10 @@ _cdns_xfer_msg(struct sdw_cdns *cdns, struct sdw_msg *msg, int cmd, dev_err(cdns->dev, "IO transfer timed out, cmd %d device %d addr %x len %d\n", cmd, msg->dev_num, msg->addr, msg->len); msg->len = 0; + + /* Drain anything in the RX_FIFO */ + cdns_read_response(cdns); + return SDW_CMD_TIMEOUT; } @@ -769,29 +796,6 @@ EXPORT_SYMBOL(cdns_read_ping_status); * IRQ handling */ -static void cdns_read_response(struct sdw_cdns *cdns) -{ - u32 num_resp, cmd_base; - int i; - - /* RX_FIFO_AVAIL can be 2 entries more than the FIFO size */ - BUILD_BUG_ON(ARRAY_SIZE(cdns->response_buf) < CDNS_MCP_CMD_LEN + 2); - - num_resp = cdns_readl(cdns, CDNS_MCP_FIFOSTAT); - num_resp &= CDNS_MCP_RX_FIFO_AVAIL; - if (num_resp > ARRAY_SIZE(cdns->response_buf)) { - dev_warn(cdns->dev, "RX AVAIL %d too long\n", num_resp); - num_resp = ARRAY_SIZE(cdns->response_buf); - } - - cmd_base = CDNS_MCP_CMD_BASE; - - for (i = 0; i < num_resp; i++) { - cdns->response_buf[i] = cdns_readl(cdns, cmd_base); - cmd_base += CDNS_MCP_CMD_WORD_LEN; - } -} - static int cdns_update_slave_status(struct sdw_cdns *cdns, u64 slave_intstat) { -- 2.39.2