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 038E3C77B7F for ; Mon, 8 May 2023 10:42:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234959AbjEHKm2 (ORCPT ); Mon, 8 May 2023 06:42:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234961AbjEHKlw (ORCPT ); Mon, 8 May 2023 06:41:52 -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 05B022A86F for ; Mon, 8 May 2023 03:41:14 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 61FC862845 for ; Mon, 8 May 2023 10:41:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59A37C433EF; Mon, 8 May 2023 10:41:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683542472; bh=2Qu7lRMkpiCSdzL9Wn0xhzrbliIZ6NffpuHSJYKR8Vc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vcd6h/52S46NwaRI2Ltc3ZNUjyjoIHW2DrnqhJFNuMGzuMrP9tlUG/v8nmjIcRQZE +omiS28oOMZyd7bi27eYo4Kbgx8gnyl3Nkwqvno7gaz7AbrlCuBcecoaiussUzQW+8 JH1u7L6meySwEP99seIceZ5IaQqVl/RVTFdRWjmE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Doug Berger , Florian Fainelli , Sasha Levin Subject: [PATCH 6.2 446/663] serial: 8250_bcm7271: Fix arbitration handling Date: Mon, 8 May 2023 11:44:32 +0200 Message-Id: <20230508094442.553159955@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094428.384831245@linuxfoundation.org> References: <20230508094428.384831245@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: Doug Berger [ Upstream commit 15ac1122fd6d4bf408a03e6f23c7ad4f60b22f9e ] The arbitration of the UART DMA is mishandled for a few exceptional cases when probing and releasing the driver. It is possible that the DMA register spaces are not defined in device tree for an instance of the driver, so attempts to access the registers in brcmuart_arbitration() would use NULL pointers. It is also possible for the probe function to return an error while still holding the UART DMA. This would prevent the UART DMA from being claimed by an instance that could use it. These errors are addressed by only releasing the UART DMA if it is held by this instance (i.e. priv->dma_enabled == 1) and directing early error paths in probe to this common release_dma handling. Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver") Signed-off-by: Doug Berger Acked-by: Florian Fainelli Link: https://lore.kernel.org/r/20230309190224.687380-1-opendmb@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/8250/8250_bcm7271.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c index ed5a947476920..f801b1f5b46c0 100644 --- a/drivers/tty/serial/8250/8250_bcm7271.c +++ b/drivers/tty/serial/8250/8250_bcm7271.c @@ -1014,14 +1014,16 @@ static int brcmuart_probe(struct platform_device *pdev) /* See if a Baud clock has been specified */ baud_mux_clk = of_clk_get_by_name(np, "sw_baud"); if (IS_ERR(baud_mux_clk)) { - if (PTR_ERR(baud_mux_clk) == -EPROBE_DEFER) - return -EPROBE_DEFER; + if (PTR_ERR(baud_mux_clk) == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + goto release_dma; + } dev_dbg(dev, "BAUD MUX clock not specified\n"); } else { dev_dbg(dev, "BAUD MUX clock found\n"); ret = clk_prepare_enable(baud_mux_clk); if (ret) - return ret; + goto release_dma; priv->baud_mux_clk = baud_mux_clk; init_real_clk_rates(dev, priv); clk_rate = priv->default_mux_rate; @@ -1029,7 +1031,8 @@ static int brcmuart_probe(struct platform_device *pdev) if (clk_rate == 0) { dev_err(dev, "clock-frequency or clk not defined\n"); - return -EINVAL; + ret = -EINVAL; + goto release_dma; } dev_dbg(dev, "DMA is %senabled\n", priv->dma_enabled ? "" : "not "); @@ -1116,7 +1119,9 @@ static int brcmuart_probe(struct platform_device *pdev) serial8250_unregister_port(priv->line); err: brcmuart_free_bufs(dev, priv); - brcmuart_arbitration(priv, 0); +release_dma: + if (priv->dma_enabled) + brcmuart_arbitration(priv, 0); return ret; } @@ -1128,7 +1133,8 @@ static int brcmuart_remove(struct platform_device *pdev) hrtimer_cancel(&priv->hrt); serial8250_unregister_port(priv->line); brcmuart_free_bufs(&pdev->dev, priv); - brcmuart_arbitration(priv, 0); + if (priv->dma_enabled) + brcmuart_arbitration(priv, 0); return 0; } -- 2.39.2