From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: Re: [PATCH v2 2/5] async_tx: Handle DMA devices having support for fewer PQ coefficients Date: Tue, 7 Feb 2017 10:16:57 -0800 Message-ID: References: <1486455406-11202-1-git-send-email-anup.patel@broadcom.com> <1486455406-11202-3-git-send-email-anup.patel@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Vinod Koul , Rob Herring , Mark Rutland , Herbert Xu , "David S . Miller" , Jassi Brar , Ray Jui , Scott Branden , Jon Mason , Rob Rice , BCM Kernel Feedback , "dmaengine@vger.kernel.org" , Device Tree , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , linux-crypto@vger.kernel.org, linux-raid To: Anup Patel Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Tue, Feb 7, 2017 at 1:02 AM, Anup Patel wrote: > On Tue, Feb 7, 2017 at 1:57 PM, Dan Williams wrote: >> On Tue, Feb 7, 2017 at 12:16 AM, Anup Patel wrote: >>> The DMAENGINE framework assumes that if PQ offload is supported by a >>> DMA device then all 256 PQ coefficients are supported. This assumption >>> does not hold anymore because we now have BCM-SBA-RAID offload engine >>> which supports PQ offload with limited number of PQ coefficients. >>> >>> This patch extends async_tx APIs to handle DMA devices with support >>> for fewer PQ coefficients. >>> >>> Signed-off-by: Anup Patel >>> Reviewed-by: Scott Branden >> >> I don't like this approach. Define an interface for md to query the >> offload engine once at the beginning of time. We should not be adding >> any new extensions to async_tx. > > Even if we do capability checks in Linux MD, we still need a way > for DMAENGINE drivers to advertise number of PQ coefficients > handled by the HW. > > I agree capability checks should be done once in Linux MD but I don't > see why this has to be part of BCM-SBA-RAID driver patches. We need > separate patchsets to address limitations of async_tx framework. Right, separate enabling before we pile on new hardware support to a known broken framework. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755200AbdBGSRL (ORCPT ); Tue, 7 Feb 2017 13:17:11 -0500 Received: from mail-oi0-f46.google.com ([209.85.218.46]:36391 "EHLO mail-oi0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754479AbdBGSRI (ORCPT ); Tue, 7 Feb 2017 13:17:08 -0500 MIME-Version: 1.0 In-Reply-To: References: <1486455406-11202-1-git-send-email-anup.patel@broadcom.com> <1486455406-11202-3-git-send-email-anup.patel@broadcom.com> From: Dan Williams Date: Tue, 7 Feb 2017 10:16:57 -0800 Message-ID: Subject: Re: [PATCH v2 2/5] async_tx: Handle DMA devices having support for fewer PQ coefficients To: Anup Patel Cc: Vinod Koul , Rob Herring , Mark Rutland , Herbert Xu , "David S . Miller" , Jassi Brar , Ray Jui , Scott Branden , Jon Mason , Rob Rice , BCM Kernel Feedback , "dmaengine@vger.kernel.org" , Device Tree , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , linux-crypto@vger.kernel.org, linux-raid Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 7, 2017 at 1:02 AM, Anup Patel wrote: > On Tue, Feb 7, 2017 at 1:57 PM, Dan Williams wrote: >> On Tue, Feb 7, 2017 at 12:16 AM, Anup Patel wrote: >>> The DMAENGINE framework assumes that if PQ offload is supported by a >>> DMA device then all 256 PQ coefficients are supported. This assumption >>> does not hold anymore because we now have BCM-SBA-RAID offload engine >>> which supports PQ offload with limited number of PQ coefficients. >>> >>> This patch extends async_tx APIs to handle DMA devices with support >>> for fewer PQ coefficients. >>> >>> Signed-off-by: Anup Patel >>> Reviewed-by: Scott Branden >> >> I don't like this approach. Define an interface for md to query the >> offload engine once at the beginning of time. We should not be adding >> any new extensions to async_tx. > > Even if we do capability checks in Linux MD, we still need a way > for DMAENGINE drivers to advertise number of PQ coefficients > handled by the HW. > > I agree capability checks should be done once in Linux MD but I don't > see why this has to be part of BCM-SBA-RAID driver patches. We need > separate patchsets to address limitations of async_tx framework. Right, separate enabling before we pile on new hardware support to a known broken framework. From mboxrd@z Thu Jan 1 00:00:00 1970 From: dan.j.williams@intel.com (Dan Williams) Date: Tue, 7 Feb 2017 10:16:57 -0800 Subject: [PATCH v2 2/5] async_tx: Handle DMA devices having support for fewer PQ coefficients In-Reply-To: References: <1486455406-11202-1-git-send-email-anup.patel@broadcom.com> <1486455406-11202-3-git-send-email-anup.patel@broadcom.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Feb 7, 2017 at 1:02 AM, Anup Patel wrote: > On Tue, Feb 7, 2017 at 1:57 PM, Dan Williams wrote: >> On Tue, Feb 7, 2017 at 12:16 AM, Anup Patel wrote: >>> The DMAENGINE framework assumes that if PQ offload is supported by a >>> DMA device then all 256 PQ coefficients are supported. This assumption >>> does not hold anymore because we now have BCM-SBA-RAID offload engine >>> which supports PQ offload with limited number of PQ coefficients. >>> >>> This patch extends async_tx APIs to handle DMA devices with support >>> for fewer PQ coefficients. >>> >>> Signed-off-by: Anup Patel >>> Reviewed-by: Scott Branden >> >> I don't like this approach. Define an interface for md to query the >> offload engine once at the beginning of time. We should not be adding >> any new extensions to async_tx. > > Even if we do capability checks in Linux MD, we still need a way > for DMAENGINE drivers to advertise number of PQ coefficients > handled by the HW. > > I agree capability checks should be done once in Linux MD but I don't > see why this has to be part of BCM-SBA-RAID driver patches. We need > separate patchsets to address limitations of async_tx framework. Right, separate enabling before we pile on new hardware support to a known broken framework.