From patchwork Thu Aug 19 15:40:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Coelho X-Patchwork-Id: 500855 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14146C432BE for ; Thu, 19 Aug 2021 15:40:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F147260C41 for ; Thu, 19 Aug 2021 15:40:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240575AbhHSPlU (ORCPT ); Thu, 19 Aug 2021 11:41:20 -0400 Received: from paleale.coelho.fi ([176.9.41.70]:56908 "EHLO farmhouse.coelho.fi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S240526AbhHSPlU (ORCPT ); Thu, 19 Aug 2021 11:41:20 -0400 Received: from 91-156-6-193.elisa-laajakaista.fi ([91.156.6.193] helo=kveik.lan) by farmhouse.coelho.fi with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1mGk9o-002Hje-Iw; Thu, 19 Aug 2021 18:40:42 +0300 From: Luca Coelho To: kvalo@codeaurora.org Cc: luca@coelho.fi, linux-wireless@vger.kernel.org Date: Thu, 19 Aug 2021 18:40:28 +0300 Message-Id: X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210819154035.72584-1-luca@coelho.fi> References: <20210819154035.72584-1-luca@coelho.fi> MIME-Version: 1.0 Subject: [PATCH 04/11] iwlwifi: pcie: avoid dma unmap/remap in crash dump Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Johannes Berg DMA-API debug code pointed out that in this code path we never check the return value of dma_map_page(), which could fail. However, we don't really even want to unmap/remap, we just want to ensure that we can actually access the last version of the data that the (now-dead) device may have written, so only need to dma_sync_single_for_cpu() instead. Signed-off-by: Johannes Berg Signed-off-by: Luca Coelho --- drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c index 86a949440486..1e6af3cbe026 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c @@ -2968,8 +2968,8 @@ static u32 iwl_trans_pcie_dump_rbs(struct iwl_trans *trans, struct iwl_rx_mem_buffer *rxb = rxq->queue[i]; struct iwl_fw_error_dump_rb *rb; - dma_unmap_page(trans->dev, rxb->page_dma, max_len, - DMA_FROM_DEVICE); + dma_sync_single_for_cpu(trans->dev, rxb->page_dma, + max_len, DMA_FROM_DEVICE); rb_len += sizeof(**data) + sizeof(*rb) + max_len; @@ -2978,10 +2978,6 @@ static u32 iwl_trans_pcie_dump_rbs(struct iwl_trans *trans, rb = (void *)(*data)->data; rb->index = cpu_to_le32(i); memcpy(rb->data, page_address(rxb->page), max_len); - /* remap the page for the free benefit */ - rxb->page_dma = dma_map_page(trans->dev, rxb->page, - rxb->offset, max_len, - DMA_FROM_DEVICE); *data = iwl_fw_error_next_data(*data); }