From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 872B5C43218 for ; Fri, 26 Apr 2019 09:37:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C59C206BA for ; Fri, 26 Apr 2019 09:37:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726058AbfDZJhk (ORCPT ); Fri, 26 Apr 2019 05:37:40 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:34459 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725935AbfDZJhf (ORCPT ); Fri, 26 Apr 2019 05:37:35 -0400 Received: from kresse.hi.pengutronix.de ([2001:67c:670:100:1d::2a]) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1hJxIK-0004Mr-LY; Fri, 26 Apr 2019 11:37:24 +0200 Message-ID: <1556271442.2584.29.camel@pengutronix.de> Subject: Re: [EXT] Re: [PATCH v2 06/15] spi: imx: fix ERR009165 From: Lucas Stach To: Robin Gong , "robh+dt@kernel.org" , "u.kleine-koenig@pengutronix.de" , "festevam@gmail.com" , "plyatov@gmail.com" , "broonie@kernel.org" , "dan.j.williams@intel.com" , "mark.rutland@arm.com" , "catalin.marinas@arm.com" , "will.deacon@arm.com" , "shawnguo@kernel.org" , "s.hauer@pengutronix.de" Cc: "linux-spi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "dmaengine@vger.kernel.org" , dl-linux-imx , "kernel@pengutronix.de" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Date: Fri, 26 Apr 2019 11:37:22 +0200 In-Reply-To: <1556270196.9298.16.camel@nxp.com> References: <1556265512-9130-1-git-send-email-yibin.gong@nxp.com> <1556265512-9130-7-git-send-email-yibin.gong@nxp.com> <1556269635.2584.23.camel@pengutronix.de> <1556270196.9298.16.camel@nxp.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::2a X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: dmaengine@vger.kernel.org Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org Message-ID: <20190426093722.ri-pnBhumvyUPqxYRYeSsm_mXX_FVCIVkMrG6vmP_hM@z> Am Freitag, den 26.04.2019, 09:22 +0000 schrieb Robin Gong: > On 2019-04-26 at 11:07 +0200, Lucas Stach wrote: > > > > Am Freitag, den 26.04.2019, 08:05 +0000 schrieb Robin Gong: > > >  static void mx51_setup_wml(struct spi_imx_data *spi_imx) > > >  { > > > +     u32 tx_wml = 0; > > > + > > > > With a wml of 0 you might set the maxburst of the TX dma channel to > > fifosize to minimize the performance impact of this workaround. > > > > Regards, > > Lucas > > Unfortunately, this is a MUST part of errata which cause performance > drop. I'm not talking about changing the WML, but when the WML must be 0 you can safely increase the DMA burst size without overflowing the FIFO, which might recover some of of the performance loss. Regards, Lucas