From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F3563E716E for ; Tue, 17 Mar 2026 14:46:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773758799; cv=none; b=B4crNKe3s1Dsejn/y8GLxCKCE3pJRejbhH5k47FN52PaN0d2W200dMkmWYkCHrdK8UGOuR1KlvBz/KEhqSN/xVIxxGu0RxZBx8Guwte903LFc9W6DlZGX0I8FCkJlar7l9QB7qt8vvYQj1mlEAxHutpsVgGuVcbNDuMjmON1jY0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773758799; c=relaxed/simple; bh=q80W9jujsavU8icRal3t+yZvbfbwc3k6ZLbpeLnFUnI=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=cioyLL8kbs895cDAANL+YEtuJjkcEAFk0EGIP2C/ZizAfgDGUFkaDyXBzIKeD7Y7BeoogaCntJu4ryN1WAFOsxxxZ4ujPv3e9UNC2CS8WvPcMCA8JfVZeq1YvQUxRZVimclFxcqgUWGI/O3N1oWiLysJcM9SvlKvUpMCa+E9T3E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PTuGPfUM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="PTuGPfUM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A7ACC4CEF7; Tue, 17 Mar 2026 14:46:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1773758798; bh=q80W9jujsavU8icRal3t+yZvbfbwc3k6ZLbpeLnFUnI=; h=Subject:To:Cc:From:Date:From; b=PTuGPfUMvzE7j2pyV8aD8ooRqW5k0THjUsNKt/D0Er4w1/6V6Wl66CeHGkzfEsv4E fjXCuoP9/UY4lTJmIOA8lvkoEL5l+dhPnrqcQJeIW7jMtk2PlnKnYGkiTF1V6KuNn4 QY//sZWPnC8TLzLdT8i0h8eLqlSdkhUocWQU5NJ4= Subject: FAILED: patch "[PATCH] i3c: mipi-i3c-hci: Fix race in DMA ring dequeue" failed to apply to 6.6-stable tree To: adrian.hunter@intel.com,Frank.Li@nxp.com,alexandre.belloni@bootlin.com Cc: From: Date: Tue, 17 Mar 2026 15:46:26 +0100 Message-ID: <2026031726-collar-blunderer-a5d4@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 1dca8aee80eea76d2aae21265de5dd64f6ba0f09 # git commit -s git send-email --to '' --in-reply-to '2026031726-collar-blunderer-a5d4@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1dca8aee80eea76d2aae21265de5dd64f6ba0f09 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 6 Mar 2026 09:24:43 +0200 Subject: [PATCH] i3c: mipi-i3c-hci: Fix race in DMA ring dequeue The HCI DMA dequeue path (hci_dma_dequeue_xfer()) may be invoked for multiple transfers that timeout around the same time. However, the function is not serialized and can race with itself. When a timeout occurs, hci_dma_dequeue_xfer() stops the ring, processes incomplete transfers, and then restarts the ring. If another timeout triggers a parallel call into the same function, the two instances may interfere with each other - stopping or restarting the ring at unexpected times. Add a mutex so that hci_dma_dequeue_xfer() is serialized with respect to itself. Fixes: 9ad9a52cce282 ("i3c/master: introduce the mipi-i3c-hci driver") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260306072451.11131-7-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c index faf5eae2409f..061e84a5c412 100644 --- a/drivers/i3c/master/mipi-i3c-hci/core.c +++ b/drivers/i3c/master/mipi-i3c-hci/core.c @@ -927,6 +927,7 @@ static int i3c_hci_probe(struct platform_device *pdev) return -ENOMEM; spin_lock_init(&hci->lock); + mutex_init(&hci->control_mutex); /* * Multi-bus instances share the same MMIO address range, but not diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index 74b255ad6d0f..f7d411e5e11f 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -547,6 +547,8 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, unsigned int i; bool did_unqueue = false; + guard(mutex)(&hci->control_mutex); + /* stop the ring */ rh_reg_write(RING_CONTROL, RING_CTRL_ABORT); if (wait_for_completion_timeout(&rh->op_done, HZ) == 0) { diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h index f1dd502c071f..9c63d80f7fc4 100644 --- a/drivers/i3c/master/mipi-i3c-hci/hci.h +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h @@ -51,6 +51,7 @@ struct i3c_hci { void *io_data; const struct hci_cmd_ops *cmd; spinlock_t lock; + struct mutex control_mutex; atomic_t next_cmd_tid; bool irq_inactive; u32 caps;