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 7BC44D78785 for ; Fri, 19 Dec 2025 14:45:54 +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=5AQYm57nFGaHWtBlPgqV0dxek9kX76miGIvu46mu7OE=; b=N3PwVqRFZ0ZmUu 7IMbL9V9lGPiFuO0ICRoks7a6rRsppMzILuGChT/LrgZOPl1OLaT6XnwYPaZwF8mEIPnexdrWpZ0P l2aW5Dn2LFE3iGBZhdN8ApmYWI+1570Jj4AUci1Vx2C83PBsKICLkvu2yXzRo8NwTpywQi15WFFLe z9mWFwqzmdLKTIr2dyfZsqgAj9PoONSvV6klPSvfVbV9dNZ1eeXneWV9odjFIz6pOG5viJc2UpHE5 le/bLW9GUPARhsVJmjzEXVsrBfzJE0DhFSUcN8VusjyERqqoCDaAP0n6MELGWyS1WWYP9FKTDYG9J S38+J0+5rIXEWwJ+wIfQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vWbju-0000000ARNa-12ni; Fri, 19 Dec 2025 14:45:54 +0000 Received: from mgamail.intel.com ([192.198.163.7]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vWbjr-0000000ARM7-2s5B for linux-i3c@lists.infradead.org; Fri, 19 Dec 2025 14:45:52 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1766155552; x=1797691552; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=uxxuW4hVW36KHL2iiDQ7NRQbp1j4IDusxrcNYYo9quY=; b=A+FwHKNX1DZExZlMXCK8urtPBuVIec1EoUQDWxFA+HnLEormG0S8Rfh2 8BgMgF8FkSCO+QeNf63PQBSKOC95KhtLWlpnrzehCo0OCxn4QUMiGG9M+ QJKHJRFj+JeBJqCJscZ+MLXf+x3nOy8BXmggC8WtsPwm5BJEvrkTYGRcn aPY1m0k/M2sMZHSqZxluYFcsjQJ5DapAzceiqRZgim7Of5WVsCEkchFog XuU1ia0aeHxHR/ohHbObLaN2sl9SHdaUsieywq8WrIofsgXh7A6M79ECV g62p5m5gcprIp2EbUMh4Hve3q5ohDBhuPV02nOAWP14D5lDB23wDwp8Pa w==; X-CSE-ConnectionGUID: dDc3MFjnRMmeXgCv2H/lDA== X-CSE-MsgGUID: B7ls3sUgTZScM36AsHgh4A== X-IronPort-AV: E=McAfee;i="6800,10657,11646"; a="93588897" X-IronPort-AV: E=Sophos;i="6.21,161,1763452800"; d="scan'208";a="93588897" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Dec 2025 06:45:51 -0800 X-CSE-ConnectionGUID: o/zeBjecRNWfkT6R1y3lSw== X-CSE-MsgGUID: LMgjTNtoQh+BNMxOWmqIPg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,161,1763452800"; d="scan'208";a="229563919" Received: from smoticic-mobl1.ger.corp.intel.com (HELO ahunter6-desk) ([10.245.244.200]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Dec 2025 06:45:49 -0800 From: Adrian Hunter To: alexandre.belloni@bootlin.com Cc: Frank.Li@nxp.com, Wolfram Sang , Aniket , linux-i3c@lists.infradead.org Subject: [PATCH 01/17] i3c: mipi-i3c-hci: Reset RING_OPERATION1 fields during init Date: Fri, 19 Dec 2025 16:45:18 +0200 Message-ID: <20251219144534.84391-2-adrian.hunter@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251219144534.84391-1-adrian.hunter@intel.com> References: <20251219144534.84391-1-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-20251219_064551_753890_7E2E0381 X-CRM114-Status: UNSURE ( 8.36 ) 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 MIPI I3C HCI specification does not define reset values for RING_OPERATION1 fields, and some controllers (e.g., Intel) do not clear them during a software reset. Ensure the ring pointers are explicitly set to zero during bus initialization to avoid inconsistent state. Signed-off-by: Adrian Hunter --- drivers/i3c/master/mipi-i3c-hci/dma.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index 0f6bbe184e85..5515ed740ca4 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -340,6 +340,14 @@ static int hci_dma_init(struct i3c_hci *hci) rh_reg_write(INTR_SIGNAL_ENABLE, regval); ring_ready: + /* + * The MIPI I3C HCI specification does not document reset values for + * RING_OPERATION1 fields and some controllers (e.g. Intel controllers) + * do not reset the values, so ensure the ring pointers are set to zero + * here. + */ + rh_reg_write(RING_OPERATION1, 0); + rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE | RING_CTRL_RUN_STOP); } -- 2.51.0 -- linux-i3c mailing list linux-i3c@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-i3c