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 2B911D148BE for ; Thu, 8 Jan 2026 08:06:17 +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=PE0FGicZnlwoDdE5Q7nhSU6DwrTouajEdsq2OWjJrq0=; b=FdWbaZf2nHZsir kmGVyRnRyK/u3RxMNRjW7U9yeynHDJH0wL5HmM1YjiUVnfNV/U4DyVpjVC7nUgYrU3YFvsfVucWSL veYSqhBlV0YnI1TBlBw/caIaMBjz67jRT9LvkRVrZMq1z5VR6ZprKfRndbWFsBnu5VwThXj++Xftj RDhbOV3jWNUyXzkm3gFRtoM/xCTbLEFoGZlsg3gP6Vid2lHqg1SElmhxLFsnYrrnt8ioed5B2s+TN GnaHoH/l9veh3wXoZELfRhi6I7hyAWQnfBLJCD7d5Dh2f/j/eRLtgB7fT8KAeLeqf8reDGJSPGy1G 9f6kKlF6mRYH6xpYmU7Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vdl28-0000000GD2K-3qMF; Thu, 08 Jan 2026 08:06:16 +0000 Received: from mgamail.intel.com ([192.198.163.16]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vdl25-0000000GCzw-0GTQ for linux-i3c@lists.infradead.org; Thu, 08 Jan 2026 08:06:14 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1767859573; x=1799395573; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=waOZMu6mcs4CrnOgUn7ACKSU+i8zBLAXTkFPzqV8kgE=; b=KHqYskdlaQIIXMu6s/ijMRpG2dKtGQ0ZxoprI5t2PzZPNcDXtKTO3m5/ mKZBXZIyIzy28XLbqzuxOIlj3xsuHP9IwFZ49c9N9V/K4sBSleDDIQsHO qodbsjpQGgcZcc6KjTQjL9BbHjk67/mdY0Nd8SZDZ86uLIaY9D8Uy4pxU RXoCs5jXEXWRRjDdQkZ1Dke0T6WHWH5oBw3/Zx19WK7VBu/nnaiCOqE6Z ofk3W4yRurlW+4oeyMQ9EE4WjdI4anL9SheRF1BeRhuzI75Fr831Vrwkn FZfHbApQsDSDe+tbs0YyZ3AUTGu00I7naGwpU6XOcjOR7JaCrAPQqKOPu w==; X-CSE-ConnectionGUID: NQJOwzvoQlWpzjrUerslRg== X-CSE-MsgGUID: 08OjbC+sSFqVvdh13/m04w== X-IronPort-AV: E=McAfee;i="6800,10657,11664"; a="56792240" X-IronPort-AV: E=Sophos;i="6.21,210,1763452800"; d="scan'208";a="56792240" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jan 2026 00:06:13 -0800 X-CSE-ConnectionGUID: e3RzPaRyQhuFPY2GQJekkg== X-CSE-MsgGUID: GGcj/3MPQEmZ8vVFRhq23w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,210,1763452800"; d="scan'208";a="203413560" Received: from abityuts-desk.ger.corp.intel.com (HELO ahunter6-desk) ([10.245.245.195]) by fmviesa008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jan 2026 00:06:11 -0800 From: Adrian Hunter To: alexandre.belloni@bootlin.com Cc: Frank.Li@nxp.com, Wolfram Sang , Aniket , linux-i3c@lists.infradead.org Subject: [PATCH V2 01/20] i3c: mipi-i3c-hci: Reset RING_OPERATION1 fields during init Date: Thu, 8 Jan 2026 10:05:39 +0200 Message-ID: <20260108080558.21767-2-adrian.hunter@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260108080558.21767-1-adrian.hunter@intel.com> References: <20260108080558.21767-1-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-20260108_000613_111326_28CFB796 X-CRM114-Status: UNSURE ( 8.04 ) 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 Reviewed-by: Frank Li --- Changes in V2: Add Frank's Rev'd-by 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