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 X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 CEEA0C47084 for ; Mon, 24 May 2021 14:47:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B36EA613F6 for ; Mon, 24 May 2021 14:47:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233521AbhEXOsx (ORCPT ); Mon, 24 May 2021 10:48:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:54806 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233294AbhEXOsX (ORCPT ); Mon, 24 May 2021 10:48:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EADF0613E4; Mon, 24 May 2021 14:46:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621867615; bh=FjffVfX7ZHBpMoEV5UGia/iEkAw5C7P7xXuBqUhqT+g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=immYRoEAZ2prWcZjA384AZd1D2C6fV68g071QmwiVbvXbWKnq++01yCq0c41w43T2 BXxLQIZcENnNbkPHJFOS6k0f+KS7+o/Ofaheut8gB8VnhMosRTU5A2oJqctOo4uilr rFsqD0LWDtZU+rUzXOS4JVBZRh+CMe6/huW2mQHUX7SlLtuSd7u4n2gAD3+TASVu7r sJKRaobRc/lFwNvIWT+sYg0tKIx/jIwXDe/aLcev8vV4woN+/svJUXsMlGefnZUu5/ HMaX+/JTBTIuR0y5XArXADjznaaVhqL2Lr628vde7LZBd57zn/AUuxEkllWaZqEfaQ EgDEizOH1HUKg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Phillip Potter , Vinod Koul , Sinan Kaya , Greg Kroah-Hartman , Sasha Levin , linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, dmaengine@vger.kernel.org Subject: [PATCH AUTOSEL 5.12 26/63] dmaengine: qcom_hidma: comment platform_driver_register call Date: Mon, 24 May 2021 10:45:43 -0400 Message-Id: <20210524144620.2497249-26-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210524144620.2497249-1-sashal@kernel.org> References: <20210524144620.2497249-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Phillip Potter [ Upstream commit 4df2a8b0ad634d98a67e540a4e18a60f943e7d9f ] Place a comment in hidma_mgmt_init explaining why success must currently be assumed, due to the cleanup issue that would need to be considered were this module ever to be unloadable or were this platform_driver_register call ever to fail. Acked-By: Vinod Koul Acked-By: Sinan Kaya Signed-off-by: Phillip Potter Link: https://lore.kernel.org/r/20210503115736.2104747-52-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/dma/qcom/hidma_mgmt.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/dma/qcom/hidma_mgmt.c b/drivers/dma/qcom/hidma_mgmt.c index fe87b01f7a4e..62026607f3f8 100644 --- a/drivers/dma/qcom/hidma_mgmt.c +++ b/drivers/dma/qcom/hidma_mgmt.c @@ -418,6 +418,20 @@ static int __init hidma_mgmt_init(void) hidma_mgmt_of_populate_channels(child); } #endif + /* + * We do not check for return value here, as it is assumed that + * platform_driver_register must not fail. The reason for this is that + * the (potential) hidma_mgmt_of_populate_channels calls above are not + * cleaned up if it does fail, and to do this work is quite + * complicated. In particular, various calls of of_address_to_resource, + * of_irq_to_resource, platform_device_register_full, of_dma_configure, + * and of_msi_configure which then call other functions and so on, must + * be cleaned up - this is not a trivial exercise. + * + * Currently, this module is not intended to be unloaded, and there is + * no module_exit function defined which does the needed cleanup. For + * this reason, we have to assume success here. + */ platform_driver_register(&hidma_mgmt_driver); return 0; -- 2.30.2