From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9AC2B33A01E; Sat, 28 Feb 2026 17:33:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772300033; cv=none; b=dKr8dXyH2mc7BVwfzk2ehF/fcIBLak3GpzZDOpz9p3OPl6DyKpAJxRsva8Cqj0oq7EBom9Fr01cYlf64d9OwZIHDHmWhgT5Pb5pIO1hd5w1bVLe/MAt1bVCZ6u8dW+rMiHorTySBIsWt1SD31sUIZsBkVB+MCRpTcxKVWbiapm8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772300033; c=relaxed/simple; bh=iv7VVudKM1I3hlT9k5+PCMCP6tgXzG9LZ2Dv/FdCcbk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WMoAcjFzsktvT5Q5aAkHjF8ctvhS9nUwx/0jslV0hlwccoDrtjM21hb640lHr740ZUrw13JR4+RM/z5hagL9SmoFxrn5XfMedFzNKLda0PCqC9aeo5naBeBm8LSjLm4t6Pjw7A68Fbnbtg8cbJ3PaFiYndPDsMaEQIwG4DLOuc0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=S2IIWYqI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="S2IIWYqI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3853C2BC9E; Sat, 28 Feb 2026 17:33:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772300033; bh=iv7VVudKM1I3hlT9k5+PCMCP6tgXzG9LZ2Dv/FdCcbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S2IIWYqIf5BpIWUo3NvABgdA1tcvEfwbelncS8UOOEg7ZnWgEr+5kvE5qF/tDycpk Lzp14zcKWDRXkbkIYg5qvTihEk+74peOOTGUhoI0RoxoMxo1wgbZhyBt2fZxp661RY HUAfmBZ8lmBoPhil43L1RvGV4h/jUsqropZYijdMHSVD7HLy/sIsIBSnZ5IfAJe9FY 9O2tuRFQxXHNw+ERAfkQXUg0++gTk3xGaq/4vZ9fwPPN3a5RzNZdN/BVsAaA8XIbrf zV1bAuWCafd8CB0Z/dOWTJsFhC6cz7r1y9b5aD0ShB4xQJZWDaMe+szv3jFTInzJHw 7hUrSG0h5/yvA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Adrian Hunter , Frank Li , Alexandre Belloni , Sasha Levin Subject: [PATCH 6.19 045/844] i3c: mipi-i3c-hci: Reset RING_OPERATION1 fields during init Date: Sat, 28 Feb 2026 12:19:18 -0500 Message-ID: <20260228173244.1509663-46-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228173244.1509663-1-sashal@kernel.org> References: <20260228173244.1509663-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Adrian Hunter [ Upstream commit 78f63ae4a82db173f93adca462e63d11ba06b126 ] 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 Link: https://patch.msgid.link/20260113072702.16268-2-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni Signed-off-by: Sasha Levin --- 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 c401a9425cdc5..951abfea5a6fd 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -342,6 +342,14 @@ 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