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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76901EE49A4 for ; Tue, 22 Aug 2023 13:24:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236092AbjHVNYn (ORCPT ); Tue, 22 Aug 2023 09:24:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229805AbjHVNYn (ORCPT ); Tue, 22 Aug 2023 09:24:43 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA99618B; Tue, 22 Aug 2023 06:24:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1692710679; x=1724246679; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=Oyh1DVtXWTFJxIjmbrfImZE0rxDAK+zFpWsXtCZGakM=; b=PnWckcIb2oCT+5fv6GE4B/p7RhiC9mcdoMXL9d7zk94rQSmrY8bMOO9Q 92AI53Jf+NmnTR1zxYwlyR02IyaFfo6nab7Mh1hEVCm9+BJpRTwwJE52v RcyypPoaq3WbLI0bH4jS92lw2brIT7NivH4+ydWMuUXKYdAmVCoABorFU hbmtSlw/m5O1dT7D6ItZz1f/ggQgFU47D1whc6kISJkVLpNEq/eQ6VDNU Gju29grh/VYfGFcA3PTtTA3mpZLtpD0U67smUyjySBnvx9zSMAm5wiXtk kofnt/8egXzrXtCRWCCF9S2zOU2IDp1OrigzqJMzU5f47yuoeqrd0AkTX g==; X-IronPort-AV: E=McAfee;i="6600,9927,10809"; a="376613689" X-IronPort-AV: E=Sophos;i="6.01,193,1684825200"; d="scan'208";a="376613689" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Aug 2023 06:24:37 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10809"; a="859920517" X-IronPort-AV: E=Sophos;i="6.01,193,1684825200"; d="scan'208";a="859920517" Received: from refaase-mobl.ger.corp.intel.com ([10.252.53.244]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Aug 2023 06:24:33 -0700 Date: Tue, 22 Aug 2023 16:24:31 +0300 (EEST) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: Feiyang Chen cc: bhelgaas@google.com, rafael.j.wysocki@intel.com, mika.westerberg@linux.intel.com, helgaas@kernel.org, anders.roxell@linaro.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, guyinggang@loongson.cn, siyanteng@loongson.cn, chenhuacai@loongson.cn, loongson-kernel@lists.loongnix.cn, chris.chenfeiyang@gmail.com Subject: Re: [PATCH v2] PCI/PM: Only read PCI_PM_CTRL register when available In-Reply-To: <20230822115514.999111-1-chenfeiyang@loongson.cn> Message-ID: References: <20230822115514.999111-1-chenfeiyang@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Tue, 22 Aug 2023, Feiyang Chen wrote: > When the current state is already PCI_D0, pci_power_up() will return > 0 even though dev->pm_cap is not set. In that case, we should not > read the PCI_PM_CTRL register in pci_set_full_power_state(). IMHO, this is a bit misleading because after this patch, pci_power_up() returns always an error if dev->pm_cap is not set. -- i. > Fixes: e200904b275c ("PCI/PM: Split pci_power_up()") > Signed-off-by: Feiyang Chen > --- > drivers/pci/pci.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 60230da957e0..7e90ab7b47a1 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -1242,9 +1242,6 @@ int pci_power_up(struct pci_dev *dev) > else > dev->current_state = state; > > - if (state == PCI_D0) > - return 0; > - > return -EIO; > } > > @@ -1302,8 +1299,12 @@ static int pci_set_full_power_state(struct pci_dev *dev) > int ret; > > ret = pci_power_up(dev); > - if (ret < 0) > + if (ret < 0) { > + if (dev->current_state == PCI_D0) > + return 0; > + > return ret; > + } > > pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); > dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK; >