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 BD61CF94CA4 for ; Tue, 21 Apr 2026 17:55:22 +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=+QaGCSYiUnGTR6dZLgBKkrqknQ3fp22BOsGbFi2SjdA=; b=Qc9RE5UXUY5sAQ PAJXj1H5UgimTQC/aLz9XeCSy7dO5h96rr/0bJtqhjltP+x72r7WIPMMHJKaJTbsIKWwozcjXGnuc bSDzts7FWWzFnD4EQj9PQ4S3twJJrj/hpG6i7D6gdGQ6zouIgwa5WfRiciNsavaeVljPWA90gY9Fy 0hzUttsvhX/9F9YKppHqqreAjayseF53fLMVci0z6eYIF547PlvZFsRhfS8ojeddWY3cWS0YKa736 nmzkhgYNveS7jHKUDysfkKcTDhRbOH8mB5pw8Gf9pwD4ujC2yDFj/BKq2MEsks/bVMi75S+UioMS1 pAadRDkE9ANz+UGU918Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wFFJi-00000008zlp-1xWW; Tue, 21 Apr 2026 17:55:22 +0000 Received: from mgamail.intel.com ([198.175.65.19]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wFFJc-00000008zif-3DHA for linux-i3c@lists.infradead.org; Tue, 21 Apr 2026 17:55:19 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1776794117; x=1808330117; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=RpEY96fL+nmr8av+bIMbFv4/Mbf49/G5xKR0aiomEKQ=; b=KlJnSL/LX6iXaWzPPH+aPSlMuBVZFEkw1nIQblJesDvvgt4jNMVea18J BtvTtAO0LIlLFdzMdxenzWXqs2cSV17xTQlAsnVzPc909zaMkgpk3ZU15 5Im3wa7R52XJRR3ur41foGe35YKM3/g7P0BB5xUbPeLGShxcCdRW6t/YH E29s9KqgR5CoLEnQGXuj2KSh+5WTNHvdLJrt15AzPihWzoRgaviy6htsT YS0pAbfEmSJEGlzCbfTHtRzFc/IisrytB1wUW1RpwRtt4N5+NaC2IQ6B+ 4bi7ToU9Vzt1eDQtKciSWhqmsTg1EvySOgWYI8YP8nvDei+D5XC6C5CC7 w==; X-CSE-ConnectionGUID: 1X5CsR0FSemyBIGggPp64w== X-CSE-MsgGUID: rKkm3i/RQPqgfGPe3BAgqw== X-IronPort-AV: E=McAfee;i="6800,10657,11763"; a="77651443" X-IronPort-AV: E=Sophos;i="6.23,192,1770624000"; d="scan'208";a="77651443" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2026 10:55:16 -0700 X-CSE-ConnectionGUID: IOJwsHPMSp+vghN35tFTuA== X-CSE-MsgGUID: cm5wJJnhS1Cr0nQslXuHkQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,192,1770624000"; d="scan'208";a="227495095" Received: from hrotuna-mobl2.ger.corp.intel.com (HELO ahunter6-desk) ([10.245.244.242]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2026 10:55:15 -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 V2 16/16] i3c: mipi-i3c-hci: Increase DMA transfer ring size to maximum Date: Tue, 21 Apr 2026 20:54:35 +0300 Message-ID: <20260421175435.122094-17-adrian.hunter@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260421175435.122094-1-adrian.hunter@intel.com> References: <20260421175435.122094-1-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 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260421_105516_908725_6DB89746 X-CRM114-Status: UNSURE ( 9.37 ) X-CRM114-Notice: Please train this message. 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 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 --- Changes in V2: None 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 73fd86b6fb17..3d8fa0e5ed67 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 -- linux-i3c mailing list linux-i3c@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-i3c