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 5207F171079; Wed, 17 Apr 2024 17:03:29 +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=1713373409; cv=none; b=djQswGIQfjyFbPKDSuHyzwS6SP8x0cprZ3n4TjKXqsYncV5IY3KVucRkZxX9Abuga0i5u8MiWk+/9z+loIZAGSKZWKK3l1hBCmMcHTZmg5BSaHR2aslEPn/4L3Kf8hj2wEythdM3WrBf6ccfwSxYGyPnEXDNEIMzfDYnH7HLJEM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713373409; c=relaxed/simple; bh=QjtQ6V3Ehbk5LLxAr33UNMioxKiRpcYG4jFh+UYBzEE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HvD51BoGQgl5RI6+hbFXuZXr5kOJRsGUUooYfCmUeuhen6hGwhyqKMVYZzadF6JdhvlX1l4dJ/LKqukTyoLYKlYUEWRuyJSbL4fv12x+6ZEE/o4IO75YJFwz8E7sPAGrLTK58nkB6h23q6/thh3merdT9xrJv32PQ1ceuwnrbjI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hHChMN57; 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="hHChMN57" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 504D6C072AA; Wed, 17 Apr 2024 17:03:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713373408; bh=QjtQ6V3Ehbk5LLxAr33UNMioxKiRpcYG4jFh+UYBzEE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hHChMN57kBOXbFM4QTwzgQyXPTNjbqinV6W7wCepAN0W6oYfeaCyE6dgKeTCTR9Xv G9gEj89fKjNhohGEO//tSrWYiXUTCgtUL61JfvkiXyV2qflbR+0Ju4n86LASM8Gklr +SYKoh/Yf160Uj7zpDeF/vPQnEA2Fv5pwxKYmY8Alo+/cv6LvvuWDJvCTvbqkdCiR+ ctIWquCQr+S1e28UlSRsRzreoUOHkqDwxVp20LMc8VqBlaN6APWAr9UHoWtlRpq7B9 DfKauiiui1p6RXPmALDG6N2WTI0W9lAOJhlx+HXi7wSDkfmilRwd2jZmRjkXkkGUhE vdQEAdyRcF6tw== Date: Wed, 17 Apr 2024 22:33:24 +0530 From: Vinod Koul To: Lizhi Hou Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, Nishad Saraf , nishad.saraf@amd.com, sonal.santan@amd.com, max.zhen@amd.com Subject: Re: [PATCH V10 1/1] dmaengine: amd: qdma: Add AMD QDMA driver Message-ID: References: <1709675352-19564-1-git-send-email-lizhi.hou@amd.com> <1709675352-19564-2-git-send-email-lizhi.hou@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On 08-04-24, 11:06, Lizhi Hou wrote: > > > +static void *qdma_get_metadata_ptr(struct dma_async_tx_descriptor *tx, > > > + size_t *payload_len, size_t *max_len) > > > +{ > > > + struct qdma_mm_vdesc *vdesc; > > > + > > > + vdesc = container_of(tx, typeof(*vdesc), vdesc.tx); > > > + if (payload_len) > > > + *payload_len = sizeof(vdesc->dev_addr); > > > + if (max_len) > > > + *max_len = sizeof(vdesc->dev_addr); > > > + > > > + return &vdesc->dev_addr; > > Can you describe what metadata is being used here for? > > The metadata is the device address the dma request will transfer > > data to / from.  Please see the example usage here: > > https://github.com/houlz0507/XRT-1/blob/qdma_v1_usage/src/runtime_src/core/pcie/driver/linux/xocl/subdev/qdma.c#L311 > > Before dmaengine_submit(), it specifies the device address. Hmmm, why is the vaddr passed like this, why not use slave_config for this -- ~Vinod