From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 62736329E5A for ; Thu, 16 Apr 2026 17:57:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776362271; cv=none; b=OFnQQA8kQsnwGwFktJzrvjlY/y4hxrQYI+f+6kjtxl0KrZHfNKB90xd2sr4hrJ9ep2A6P99GUcnz6c9UV4TDDV8B1+B44LVmnhcFTpksJowBG2+btVL0wUNU49Cr0fFN6h2lNbGL+CX5JMqD5Op1t47udAL5T7zamMXDYNKq33Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776362271; c=relaxed/simple; bh=2l1bjQ3UxJDbLGnSdNgnKS/z3CGthZ/e9ZN+hJneqKU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YRqMosCG2qhviGN+MECNaodwUXTkMxgWKoJvRG+wfiM8FVf8e4+2KqTtBkTjy0nbl9gjTIpCsyc+77eJN9sNBlC9g/Jenay7PoU11lU50CmgTVKn+jZC9Hkaa8++FxYmo+QAI/n7HTagxO3KF9wytGRz9Zctr9lv6zJ4YgAsH3o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=gmbhMQFk; arc=none smtp.client-ip=198.175.65.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="gmbhMQFk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1776362268; x=1807898268; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=2l1bjQ3UxJDbLGnSdNgnKS/z3CGthZ/e9ZN+hJneqKU=; b=gmbhMQFkNoZ5iAGquUXxlpaev71TYDJ7NlsTybWegLBnzDRYu3A6yEeG r+gDZVzkHmHjept9W3ZgWBTD3GM1Ymz8ahJ4X3053s+JWWoYbmLF4yxCg Zzu7XJYMXIjVavGINJv/PKEkihtGv4FFpJ73cxwou8j+v8O3wqO6dG2kH q3A8ATmsbZ12GTsAQC5Y85QwMngkWKwR+2QLU3qso5jfKdGF1hVl0Z26U kQeqiuf/IcARfPCA9Cb3GNIAl03HhKTmVbadC/eoQRF6+blpBodDUibc+ d3AXK23nmYicFmMrIO8du7blPzxudlgjhaMr8H+tAWl6mGaM4FQE7wfEF g==; X-CSE-ConnectionGUID: v1ePZM23SQetPrHbBzOx1g== X-CSE-MsgGUID: jnwpq1UQS86Sw6nKn6q7Lw== X-IronPort-AV: E=McAfee;i="6800,10657,11761"; a="94778430" X-IronPort-AV: E=Sophos;i="6.23,181,1770624000"; d="scan'208";a="94778430" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2026 10:57:47 -0700 X-CSE-ConnectionGUID: PaQ+QybLQbutQ0OdfkiywQ== X-CSE-MsgGUID: gSgt0mbfTHqnFxXhaPaQqA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,181,1770624000"; d="scan'208";a="235784671" Received: from abityuts-desk.ger.corp.intel.com (HELO ahunter6-desk) ([10.245.244.222]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2026 10:57:47 -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 16/16] i3c: mipi-i3c-hci: Increase DMA transfer ring size to maximum Date: Thu, 16 Apr 2026 20:57:04 +0300 Message-ID: <20260416175704.41217-17-adrian.hunter@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260416175704.41217-1-adrian.hunter@intel.com> References: <20260416175704.41217-1-adrian.hunter@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 Content-Transfer-Encoding: 8bit The DMA transfer ring is currently limited to 16 entries, despite the MIPI I3C HCI supporting up to 32 devices. When the ring lacks space for a new transfer list, the driver returns -EBUSY, which can be unexpected for clients. Increase the DMA transfer ring size to the maximum supported value of 255 entries. This effectively eliminates ring-space exhaustion in practice and avoids the complexity of adding secondary queuing mechanisms. Even at the maximum size, the memory overhead remains small (approximately 24 bytes per entry by default). Signed-off-by: Adrian Hunter --- drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index b06405a9aa7b..fdab1e2df19c 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -27,7 +27,7 @@ */ #define XFER_RINGS 1 /* max: 8 */ -#define XFER_RING_ENTRIES 16 /* max: 255 */ +#define XFER_RING_ENTRIES 255 /* max: 255 */ #define IBI_RINGS 1 /* max: 8 */ #define IBI_STATUS_RING_ENTRIES 32 /* max: 255 */ -- 2.51.0