From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (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 914C42045B7 for ; Wed, 22 Jan 2025 08:28:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737534495; cv=none; b=LW/HxMDNbpYlPT900ki6MBVbmlCDpJxMArT5X6iqwPsb3ELLFdzKOaQrEYcZTY/NC12bLaEBbYZT3B7dq+VLk+R9dDUjs/lIhSKtGQjL5XGDrRLai6Vkq/IKHsBltsxez1W+e5/80Ryv0UBCMnscWYwW9eCFA5aGgAT20XHuZps= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737534495; c=relaxed/simple; bh=Tu4m3JYNS2WOgNLvRZWFqW9xbZk1lxgTFdXLuVVF0UA=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=MxQdUvNUw3o7dcNSe1u3q0+zUo9k7m72VUdVRoOW1lsKGtDQqPBNqw4RjsF4cdweijcWlKrKl7CEkmmKs7AbdV+ctwecAsQAUdIdvj5H+pTfBU9BZq6VjieUxm91MQ2Zf4GIpSP0tJHrPBcDwnEz3ZCV449M4v02WLLSadDBE9g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=eRlQrs0T; arc=none smtp.client-ip=198.175.65.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="eRlQrs0T" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1737534494; x=1769070494; h=message-id:date:mime-version:subject:to:references:from: in-reply-to:content-transfer-encoding; bh=Tu4m3JYNS2WOgNLvRZWFqW9xbZk1lxgTFdXLuVVF0UA=; b=eRlQrs0TlkNQaYVRwFbHH65MgDS1mpoh/xwJDXnGnWZ80iWn14vGrsqR LA9dkCZ39Vu1/hJ04niBEDGRjfKmsChEKM9AyYbTcU8bdb0R0NSnzBkWv Iu/rQHknM+MK3+NfjlBlTZ+/9FeF3k09s+DxPYrLq5ZhsIqRKpWR/HGNk xqxWpRGgJNQjkltrWpvHUn1HzlTvMYGILyRDnmFjNCcN4CLIG7lZ8l/Nb 4UhOWpzf/2XuH9QK/JaUy/ZziKTHK2B86w2rcHYpyZjOrLZc9D1rmLdpR vKaX0H3ptw+e6HDeR4VMfaBQgYG5L3n8cxYzkdc1Wry/BgiTBLgbQFyMU w==; X-CSE-ConnectionGUID: 4VUIViPfRAWjBf3SmqbuSw== X-CSE-MsgGUID: LOMDN8BCSsm1KBHvV46Y9w== X-IronPort-AV: E=McAfee;i="6700,10204,11322"; a="41653910" X-IronPort-AV: E=Sophos;i="6.13,224,1732608000"; d="scan'208";a="41653910" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jan 2025 00:28:06 -0800 X-CSE-ConnectionGUID: ySUgBcSTT06/jBqx/mfX9A== X-CSE-MsgGUID: PsOHW7OeR0yx37rOQBEK/Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="144318446" Received: from mylly.fi.intel.com (HELO [10.237.72.59]) ([10.237.72.59]) by orviesa001.jf.intel.com with ESMTP; 22 Jan 2025 00:28:02 -0800 Message-ID: <82ce69fe-42fc-4199-bf78-4a147c26048a@linux.intel.com> Date: Wed, 22 Jan 2025 10:28:01 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 2/2] i3c: mipi-i3c-hci: Use DMA-safe buffer for I2C transfers To: Billy Tsai , alexandre.belloni@bootlin.com, pgaj@cadence.com, miquel.raynal@bootlin.com, conor.culhane@silvaco.com, aniketmaurya@google.com, Shyam-sundar.S-k@amd.com, wsa+renesas@sang-engineering.com, xiaopei01@kylinos.cn, Guruvendra.Punugupati@amd.com, linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org References: <20250121110756.214714-1-billy_tsai@aspeedtech.com> <20250121110756.214714-2-billy_tsai@aspeedtech.com> Content-Language: en-US From: Jarkko Nikula In-Reply-To: <20250121110756.214714-2-billy_tsai@aspeedtech.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 1/21/25 1:07 PM, Billy Tsai wrote: > The i2c_get_dma_safe_msg_buf function is used to ensure safe handling of > I2C messages in HCI DMA mode. > > Signed-off-by: Billy Tsai > --- > drivers/i3c/master/mipi-i3c-hci/core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c > index a408feac3e9e..3567cd566339 100644 > --- a/drivers/i3c/master/mipi-i3c-hci/core.c > +++ b/drivers/i3c/master/mipi-i3c-hci/core.c > @@ -382,7 +382,7 @@ static int i3c_hci_i2c_xfers(struct i2c_dev_desc *dev, > return -ENOMEM; > > for (i = 0; i < nxfers; i++) { > - xfer[i].data = i2c_xfers[i].buf; > + xfer[i].data = i2c_get_dma_safe_msg_buf(&i2c_xfers[i], 1); > xfer[i].data_len = i2c_xfers[i].len; > xfer[i].rnw = i2c_xfers[i].flags & I2C_M_RD; > hci->cmd->prep_i2c_xfer(hci, dev, &xfer[i]); This allow to remove calls to i3c_hci_alloc_safe_xfer_buf() and i3c_hci_free_safe_xfer_buf() in i3c_hci_i2c_xfers(). I was pondering the i2c_get_dma_safe_msg_buf() when making commit 4afd72876942 ("i3c: mipi-i3c-hci: Add DMA bounce buffer for private transfers") but decided to reuse the same (own) helper for both i3c_hci_priv_xfers() and i3c_hci_i2c_xfers(). In that sense I'd modify the commit log a bit that instead of ensuring safe handling patch switches from custom helper to i2c_get_dma_safe_msg_buf() and i2c_put_dma_safe_msg_buf() (please note the comment from Wolfram).