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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham 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 75DC7C07E94 for ; Fri, 4 Jun 2021 07:51:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55DC061411 for ; Fri, 4 Jun 2021 07:51:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230080AbhFDHxg (ORCPT ); Fri, 4 Jun 2021 03:53:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:38748 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229775AbhFDHxe (ORCPT ); Fri, 4 Jun 2021 03:53:34 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AAB6361411; Fri, 4 Jun 2021 07:51:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622793092; bh=XknpTdRALjODEseoLFd/CWgE9dln8BAlCe9q8toibx8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=iGNPli79xTBcjBpN+HQKAiJcX8iDJdUFIiXvz6A6V4+dxqM7HTT1DuQzR92r6w05o A5FckZ2eBTA+jnfjBER5xkXqhdX6JqzVhw8m/JS7hVkAmWiarE45A30PTEwou5mBJx 82uOFgKaNC+K78yLy8crJTjg5W9lPvEbI2dmgqqU= Date: Fri, 4 Jun 2021 09:51:29 +0200 From: Greg KH To: Kai Ye Cc: linux-accelerators@lists.ozlabs.org, linux-kernel@vger.kernel.org, linuxarm@huawei.com, zhangfei.gao@linaro.org, wangzhou1@hisilicon.com Subject: Re: [PATCH] uacce: add print information if not enable sva Message-ID: References: <1622792769-28017-1-git-send-email-yekai13@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1622792769-28017-1-git-send-email-yekai13@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 04, 2021 at 03:46:09PM +0800, Kai Ye wrote: > Add print information necessary if user not enable sva. > > Signed-off-by: Kai Ye > --- > drivers/misc/uacce/uacce.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c > index bae18ef0..fe38af8 100644 > --- a/drivers/misc/uacce/uacce.c > +++ b/drivers/misc/uacce/uacce.c > @@ -387,15 +387,22 @@ static void uacce_release(struct device *dev) > > static unsigned int uacce_enable_sva(struct device *parent, unsigned int flags) > { > + int ret; > + > if (!(flags & UACCE_DEV_SVA)) > return flags; > > flags &= ~UACCE_DEV_SVA; > > - if (iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_IOPF)) > + ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_IOPF); > + if (ret) { > + dev_err(parent, "failed to enable IOPF feature! ret = %d\n", ret); Why is this needed? Has this ever happened in real life such that the log message is now required? > return flags; > + } > > - if (iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA)) { > + ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA); > + if (ret) { > + dev_err(parent, "failed to enable SVA feature! ret = %d\n", ret); Same here, does this happen in real systems? thanks, greg k-h