From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (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 7BACA3D6CC1 for ; Tue, 21 Apr 2026 17:55:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776794117; cv=none; b=RoyItObFtvQQpDYqALU/sjShlP15whs2AxD+UoawtBgl+9REIH//yUtEAA77dMV7/8V/nBZh/cZ3owH8GdD2E7PdOuvvgh0kWuYKAcfpxIzoFG+d4aWGZnJELnjRrLuizQnSPl08niM8GNezPeM/UZODIc59VJNke9qAVn3mjx4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776794117; c=relaxed/simple; bh=RpEY96fL+nmr8av+bIMbFv4/Mbf49/G5xKR0aiomEKQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T8Axk59np3hjGVFTtPjvWg27ODALqdlg87JqM8+CafoG68L+oRgGFPmD67A3tRm4co95VD8Ylh5SuA0mseW7wBbpFXsQ6xuiA+uiB7X/1sDEdR6+I7rJ8PWd/1jHXwFqWbcwpthvOPv+XMQUgWu7GQ0maDomsQE2LKs00Ykg0o4= 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=J/j2kj03; arc=none smtp.client-ip=198.175.65.19 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="J/j2kj03" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1776794116; x=1808330116; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=RpEY96fL+nmr8av+bIMbFv4/Mbf49/G5xKR0aiomEKQ=; b=J/j2kj03uS9/TtmNWzZP8p72/f2owvHTcQbOmNdlL+6INtgIHr0ju5vc l/FVDU9YBbH35d6vYv+6rS4UB09SoXbd0OyuB9STsZcGLVPMC9xWO1T8J auQUjra3dWsX9/GbIt1AwUE9SDrDn3RuM/Uycal/jhXx7VHoQogT5yzSn 9lKbfmA8o6+y8oeXgVqCi4bJhol8NKtLgM3dsuXUgW1h2OJP0rKqsPYgI fSxAfdaCKsV/vNmBed2xyfJHy96JrXhLlUvHWBRjmDLb/GsafMS+QJJXf NFZcwLITc+XUIelyHvb4Nm2VJI4Z3KNIUOhQ2aykHR4D+t6IYgrrPNJIO g==; X-CSE-ConnectionGUID: 2XbKpsrISEyX8BVlavKabQ== X-CSE-MsgGUID: 3d02wHeFQO+l/5GUI3MiwA== X-IronPort-AV: E=McAfee;i="6800,10657,11763"; a="77651441" X-IronPort-AV: E=Sophos;i="6.23,192,1770624000"; d="scan'208";a="77651441" 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> 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 --- 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