From mboxrd@z Thu Jan 1 00:00:00 1970 From: Asutosh Das Subject: Re: Query regarding ADMA descriptor allocation Date: Sun, 13 Jan 2013 17:50:31 +0530 Message-ID: <50F2A68F.4000206@codeaurora.org> References: <50F0061F.6070509@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wolverine02.qualcomm.com ([199.106.114.251]:42481 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754651Ab3AMMUi (ORCPT ); Sun, 13 Jan 2013 07:20:38 -0500 In-Reply-To: <50F0061F.6070509@codeaurora.org> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: drzeus@drzeus.cx, linux-mmc@vger.kernel.org Hi Can you please let me know if my understanding in the below question is correct ? Thanks Asutosh On 1/11/2013 6:01 PM, Asutosh Das wrote: > Hi > In sdhci_add_host function, the number of adma descriptors allocated > are 128 and each descriptor consumes 8 bytes and 1 4byte is added in > the end like, > kmalloc((128 * 2 + 1) * 4, GFP_KERNEL); > > In sdhci_adma_table_pre function, each node in sg-list is iterated and > in case of a misaligned node, a descriptor is consumed, which means > for a single sg-node 2 descriptors were consumed. Let's say in a > situation, where there are multiple unaligned addresses in multiple sg > nodes and the sg-list length is 128, wouldn't this use up all the 128 > descriptors long before the entire sg-list is traversed ? > > > > -- Sent by a consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.