From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:35220 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751309AbbKSQFp (ORCPT ); Thu, 19 Nov 2015 11:05:45 -0500 From: Andy Lutomirski To: Matthew Garrett , Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Andy Lutomirski Subject: [PATCH] pcie_aspm: Make link_state_store consistent with link_state_show Date: Thu, 19 Nov 2015 08:05:35 -0800 Message-Id: <6ff64f0313c4e6400ef536017078e58ec3487c71.1447949082.git.luto@kernel.org> Sender: linux-pci-owner@vger.kernel.org List-ID: If CONFIG_PCIEASPM_DEBUG is set, then pci devices have a link_state attribute. Reading that attribute shows the state as a bit mask: 1 means L0S upstream, 2 means L0S downstream, and 4 means L1. Oddly, writing to link_state is inconsistent and gets translated, leading to mysterious results in which the value you store isn't comparable the value you load back out. Fix it by making link_state_store match link_state_show. Signed-off-by: Andy Lutomirski --- drivers/pci/pcie/aspm.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 317e3558a35e..e543dac8e3f2 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -834,22 +834,16 @@ static ssize_t link_state_store(struct device *dev, { struct pci_dev *pdev = to_pci_dev(dev); struct pcie_link_state *link, *root = pdev->link_state->root; - u32 val, state = 0; + u32 state; - if (kstrtouint(buf, 10, &val)) + if (kstrtouint(buf, 10, &state)) return -EINVAL; if (aspm_disabled) return -EPERM; - if (n < 1 || val > 3) + if ((state & ~ASPM_STATE_ALL) != 0) return -EINVAL; - /* Convert requested state to ASPM state */ - if (val & PCIE_LINK_STATE_L0S) - state |= ASPM_STATE_L0S; - if (val & PCIE_LINK_STATE_L1) - state |= ASPM_STATE_L1; - down_read(&pci_bus_sem); mutex_lock(&aspm_lock); list_for_each_entry(link, &link_list, sibling) { -- 2.5.0