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 C520ECD6E55 for ; Wed, 3 Jun 2026 09:08:44 +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=xJEWzXQDObwUIQM7UkaNS7r2f94ap90rjdfZJdyBUlw=; b=4Jx0xJpCpg4DE7 YU/S4HptrQp4wJn9b2Qkm1X7q+7h+VPJmxmqDVdSDpWdlroqSqeJsTQIWU10HlY6Y8+pF8FBDtk45 O7YNMhr6T0/Ruiwftwu1/N6lVbEEhmgRTm78RPxK03DVDkQYfAhtJS5lhEcD4ZiIEwojR11ED/X0z IvXNpv1WyRtrOtJOBQi6zzebkF4aRis5KjD/QjCQBNXU8D2n0ZBFToMXP+0S48MgvAxfZpbgs2EyX mPAEZHyYAciV+vHCeazn4drXYEBVjMgzC27uYHatIBxf8VXS0VUNdJmP0ayNuahvoixrpSkGyflKB OGlt15Q53PoGKylRDAeA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUhae-0000000Eg1F-2Ir1; Wed, 03 Jun 2026 09:08:44 +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 1wUhab-0000000Effy-3A52 for linux-i3c@lists.infradead.org; Wed, 03 Jun 2026 09:08:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1780477721; x=1812013721; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=U8i31m+uoQ82HkqAIhMysB7L27S+R96vCj6fh1UOFvk=; b=CUZD+AjZYHs/55GSQEunzemDLMJJ5m+EFq7ffxoDYzC1VBljYpaTBr6f Wvb3XPc5ewLQo3WXCUb1cdws7acHzZK0nx3rVkHFV998k1BE72DEhSJnY /M/ANYf11vvTOps5vqsW1bOksfw1FPp6imhfIIi0IV7MbFqOPV4W/yKlE DeoikOeu7jHDP6YKO90C/NU0XzzMEFH5tqpGtGEMFWpI8E/cAIFuAL7Pp DoPkxVHlbh890O2XpPL+3TLUt1EQJHYN4qNj2TD7SHNMhPB3QL4booF/o SVD0vWqelDjUE+lG+Cnwbuevd8fZi7Li26Wk2Hqq/VQDOmGZr7uciopf8 A==; X-CSE-ConnectionGUID: HFRNUAmVQE2rCQ2KvKDjNQ== X-CSE-MsgGUID: qY4XceA2RzmRTiRuxl9JAA== X-IronPort-AV: E=McAfee;i="6800,10657,11805"; a="91852680" X-IronPort-AV: E=Sophos;i="6.24,184,1774335600"; d="scan'208";a="91852680" 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 02:08:41 -0700 X-CSE-ConnectionGUID: QP1Yb5wXSe6tjNXdu4+W8A== X-CSE-MsgGUID: XJN9rBjDRSmcKiSwcDsv9g== 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 02:08:40 -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 17/17] i3c: mipi-i3c-hci: Increase DMA transfer ring size to maximum Date: Wed, 3 Jun 2026 12:07:54 +0300 Message-ID: <20260603090754.16252-18-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_020841_804502_EE502E40 X-CRM114-Status: UNSURE ( 9.17 ) 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 Reviewed-by: Frank Li --- Changes in V5: None Changes in V4: Add Frank's Rev'd-by Changes in V2 and V3: 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 0136f3064ada..5c6ae2055618 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