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 675BED29DDE for ; Tue, 13 Jan 2026 07:27:24 +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=YA1gcPdIj2WbABPOHHTuJwTxNAKqplSUKmZYS/nyL5g=; b=1g4i4NS4GcB3Oa OvlcJROnbnL9Ax251tMAiDdQNQBGC247da96SGTEY+QOg/hoCCmsz/Dpe/1j1CFkYFH3jv/t7vB4i BMiOqiruNpHbAFcgmC7BVZ//2fGPHDFFvWj2RvXGeFs3mAzhkwuiDZFH3KrwI/I1gZ+d32TXkfsb8 nYME/gUR9dV1nnwduYzHySKXgmU0UgTDQN3KUQaIR4neA0vCcEcxGpEkPFYYs9XhwOX10Z09cCRzV 3KSOkWk/xdHSNl1dZ9jVwKqwWQTniT6GSpu+GqRDQzp7Mx11n0YXcmix9I5Kq7/2cgNkbADWLAOJC 1+wGLzhsSmrvru6dQE2g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vfYoG-00000006ePo-0Jdc; Tue, 13 Jan 2026 07:27:24 +0000 Received: from mgamail.intel.com ([198.175.65.18]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vfYoC-00000006eOv-3DYt for linux-i3c@lists.infradead.org; Tue, 13 Jan 2026 07:27:22 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768289241; x=1799825241; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=MUu7uufXK8i/OxoJSwDMAninD9iBcDk/wgkWAwI8R9g=; b=OXmrRR54AzcxgPvdt/rXv5Rr2Dwsa9A3EsThRfC9x+iH/jZhojNv7+Qi cbQREnvifsfI2DqRdEL3RKcQYAi09AMLCPuOYGy27/8Npp6mkffE+15ld rtqVj2B+qnfMN/NTiiWHHp2eCJvgPrFo5IGBKv1FCI4i2uHEo+PO0eTkm LlrPjXM465i0o/Z0SRZkaMc5HvwOKC6GXg5PD7v3NarqSHtpWHk8fbkXu XAkeZWqmtQjsREyJoBxLdCcgBvfML44QwjTJUxiJN/GUYW4cwMWJUMtna Ps6HjUaUsswVH24IOfU5YIlyZwxY3JVKMC/1/t0ZT9iI+yP28HgNdxRXf A==; X-CSE-ConnectionGUID: /4Sj1jbTRsqGmDaArzpgUA== X-CSE-MsgGUID: 93R4vHWDR+uBMXZoPhnH1g== X-IronPort-AV: E=McAfee;i="6800,10657,11669"; a="69625416" X-IronPort-AV: E=Sophos;i="6.21,222,1763452800"; d="scan'208";a="69625416" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2026 23:27:21 -0800 X-CSE-ConnectionGUID: UNIl1aL2Q92/r33VxgjOQA== X-CSE-MsgGUID: jeqnupgnRbGpwwL3eWNxuw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,222,1763452800"; d="scan'208";a="235021059" Received: from amilburn-desk.amilburn-desk (HELO ahunter6-desk) ([10.245.245.167]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2026 23:27:19 -0800 From: Adrian Hunter To: alexandre.belloni@bootlin.com Cc: Frank.Li@nxp.com, Wolfram Sang , Aniket , linux-i3c@lists.infradead.org Subject: [PATCH V3 01/21] i3c: mipi-i3c-hci: Reset RING_OPERATION1 fields during init Date: Tue, 13 Jan 2026 09:26:42 +0200 Message-ID: <20260113072702.16268-2-adrian.hunter@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260113072702.16268-1-adrian.hunter@intel.com> References: <20260113072702.16268-1-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-20260112_232720_844107_9FF20D80 X-CRM114-Status: UNSURE ( 8.50 ) 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 V3: None 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