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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 796ACCD6E55 for ; Wed, 3 Jun 2026 09:08:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6ywfejMJ2BmeN5WtouOJEBuYTt5OHkhhyQorZYqLR6k=; b=XCj4CCRH9aKtQl kvxgSjpF5nN4GNbLraMD4X6Mu57cp1i+HpWazliagM2zluflgraJ12ASXFd0dY/vBcEorH1HgvUAw jDzmnMvCZBIabEyMVf6HLPpFM9kadAms9a6X9pViDF8XWGpHx20Al2EO2y4QiosuS60t43pEAo9UZ +VFk9eZB5TfwKBfkDFY2YxxfXKbZUsy9CQQFrnQajFd2PKxgdVv0ArBywWooWbp0Gc+6Wa0Ki8UGe /UxHW2gXZuEmf3HSB1GLwMyGZN36AT9tlWzgZvVA7dJrPxVSXH8/1KnWmGDowAfREgSexuSm8dw0R 4YUJZaq53AY6UHPPV2dA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUhaF-0000000EfhZ-0qey; Wed, 03 Jun 2026 09:08:19 +0000 Received: from mgamail.intel.com ([192.198.163.11]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUhaC-0000000Effy-1mNH for linux-i3c@lists.infradead.org; Wed, 03 Jun 2026 09:08:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1780477696; x=1812013696; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=VfVk0nSvQ64OhGZLsAGoQ13MEl4eNrUGeTRHkVeZGFQ=; b=lKUt8RrVd174fWHYeUElKKV0Um7qZRvdsSE98AZ6rGiBiII/96B5oI6Q zPs98T8JVySuSqS6h2MiSwED/E/Fvn7oT7pNoOC25octd59j+tPbp1pPP 3E7ZeNmoYNzHB98+tRpi24Lxn5Lo81BVvuVhivR9tYivEdpTaoD7D2wxr 4HDnGi7vO+9BSzafRD9pSqkQ7t3l9HFkxJiQ3OcALSW0MMA3eovRl9oia BO/REEF4H2W16hE4w9PnSYdeq6vZJ4j19UCogZLF6bUUEf9IMMuokOGIy iH1SsZE0JumcmQ9/mrHitw0b3zQ1lBy9JLjxMOpE8H7+S3/2HqfjTtVTy w==; X-CSE-ConnectionGUID: O4fceIlGStet62VORX/klA== X-CSE-MsgGUID: mTJLdWhDQza7yEDTfXSzfQ== X-IronPort-AV: E=McAfee;i="6800,10657,11805"; a="91852603" X-IronPort-AV: E=Sophos;i="6.24,184,1774335600"; d="scan'208";a="91852603" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jun 2026 02:08:16 -0700 X-CSE-ConnectionGUID: siH4FwTCS0CUwkEBkywvEg== X-CSE-MsgGUID: ub8G5ZZDQfSrPWb7y69gBA== X-ExtLoop1: 1 Received: from ijarvine-mobl1.ger.corp.intel.com (HELO ahunter6-desk) ([10.245.244.137]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jun 2026 02:08:14 -0700 From: Adrian Hunter To: alexandre.belloni@bootlin.com Cc: Frank.Li@nxp.com, linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH V5 03/17] i3c: mipi-i3c-hci: Prevent DMA enqueue while ring is aborting or in error Date: Wed, 3 Jun 2026 12:07:40 +0300 Message-ID: <20260603090754.16252-4-adrian.hunter@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260603090754.16252-1-adrian.hunter@intel.com> References: <20260603090754.16252-1-adrian.hunter@intel.com> MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo, Business Identity Code: 0357606 - 4, Domiciled in Helsinki X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260603_020816_478337_11E498B9 X-CRM114-Status: GOOD ( 17.24 ) X-BeenThere: linux-i3c@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org Block the DMA enqueue path while a Ring abort is in progress or after an error condition has been detected. Previously, new transfers could be enqueued while the DMA Ring was being aborted or while error handling was underway. This allowed enqueue and error-recovery paths to run concurrently, potentially interfering with each other and corrupting Ring state. Introduce explicit enqueue blocking and a wait queue to serialize access: enqueue operations now wait until abort or error handling has completed before proceeding. Enqueue is unblocked once the Ring is safely restarted. Note, there is only 1 ring bundle configured, and a transfer error causes the controller to halt ring (bundle) operation, so there is only ever 1 outstanding error at a time. Furthermore, a later patch ensures that only the currently active transfer list can time out. Consequently, the DMA queue will not be unblocked while there are outstanding transfer errors or timeouts. Signed-off-by: Adrian Hunter Reviewed-by: Frank Li --- Changes in V5: None Changes in V4: Add Frank's Rev'd-by Changes in V3: None Changes in V2: Improve commit message drivers/i3c/master/mipi-i3c-hci/core.c | 1 + drivers/i3c/master/mipi-i3c-hci/dma.c | 25 +++++++++++++++++++++++-- drivers/i3c/master/mipi-i3c-hci/hci.h | 2 ++ 3 files changed, 26 insertions(+), 2 deletions(-) diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c index afb0764b5e1f..44617eb3a3f1 100644 --- a/drivers/i3c/master/mipi-i3c-hci/core.c +++ b/drivers/i3c/master/mipi-i3c-hci/core.c @@ -973,6 +973,7 @@ static int i3c_hci_probe(struct platform_device *pdev) spin_lock_init(&hci->lock); mutex_init(&hci->control_mutex); + init_waitqueue_head(&hci->enqueue_wait_queue); /* * 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 bdffdd8b8923..c3da6eab8eae 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -484,6 +484,12 @@ static int hci_dma_queue_xfer(struct i3c_hci *hci, spin_lock_irq(&hci->lock); + while (unlikely(hci->enqueue_blocked)) { + spin_unlock_irq(&hci->lock); + wait_event(hci->enqueue_wait_queue, !READ_ONCE(hci->enqueue_blocked)); + spin_lock_irq(&hci->lock); + } + if (n > rh->xfer_space) { spin_unlock_irq(&hci->lock); hci_dma_unmap_xfer(hci, xfer_list, n); @@ -539,6 +545,14 @@ static int hci_dma_queue_xfer(struct i3c_hci *hci, return 0; } +static void hci_dma_unblock_enqueue(struct i3c_hci *hci) +{ + if (hci->enqueue_blocked) { + hci->enqueue_blocked = false; + wake_up_all(&hci->enqueue_wait_queue); + } +} + static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, struct hci_xfer *xfer_list, int n) { @@ -550,12 +564,17 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, guard(mutex)(&hci->control_mutex); + spin_lock_irq(&hci->lock); + ring_status = rh_reg_read(RING_STATUS); if (ring_status & RING_STATUS_RUNNING) { + hci->enqueue_blocked = true; + spin_unlock_irq(&hci->lock); /* stop the ring */ reinit_completion(&rh->op_done); rh_reg_write(RING_CONTROL, rh_reg_read(RING_CONTROL) | RING_CTRL_ABORT); wait_for_completion_timeout(&rh->op_done, HZ); + spin_lock_irq(&hci->lock); ring_status = rh_reg_read(RING_STATUS); if (ring_status & RING_STATUS_RUNNING) { /* @@ -567,8 +586,6 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, } } - spin_lock_irq(&hci->lock); - for (i = 0; i < n; i++) { struct hci_xfer *xfer = xfer_list + i; int idx = xfer->ring_entry; @@ -604,6 +621,8 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE); rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE | RING_CTRL_RUN_STOP); + hci_dma_unblock_enqueue(hci); + spin_unlock_irq(&hci->lock); return did_unqueue; @@ -647,6 +666,8 @@ static void hci_dma_xfer_done(struct i3c_hci *hci, struct hci_rh_data *rh) } if (xfer->completion) complete(xfer->completion); + if (RESP_STATUS(resp)) + hci->enqueue_blocked = true; } done_ptr = (done_ptr + 1) % rh->xfer_entries; diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h index f17f43494c1b..d630400ec945 100644 --- a/drivers/i3c/master/mipi-i3c-hci/hci.h +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h @@ -54,6 +54,8 @@ struct i3c_hci { struct mutex control_mutex; atomic_t next_cmd_tid; bool irq_inactive; + bool enqueue_blocked; + wait_queue_head_t enqueue_wait_queue; u32 caps; unsigned int quirks; unsigned int DAT_entries; -- 2.51.0 -- linux-i3c mailing list linux-i3c@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-i3c