From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754513AbbIOJKF (ORCPT ); Tue, 15 Sep 2015 05:10:05 -0400 Received: from mail.kernel.org ([198.145.29.136]:52761 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754449AbbIOJJ7 (ORCPT ); Tue, 15 Sep 2015 05:09:59 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Gabriele Mazzotta , Tejun Heo , Zefan Li Subject: [PATCH 3.4 081/146] libata: Ignore spurious PHY event on LPM policy change Date: Tue, 15 Sep 2015 17:03:16 +0800 Message-Id: <1442307861-32031-81-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1442307787-31952-1-git-send-email-lizf@kernel.org> References: <1442307787-31952-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Gabriele Mazzotta 3.4.109-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit 09c5b4803a80a5451d950d6a539d2eb311dc0fb1 upstream. When the LPM policy is set to ATA_LPM_MAX_POWER, the device might generate a spurious PHY event that cuases errors on the link. Ignore this event if it occured within 10s after the policy change. The timeout was chosen observing that on a Dell XPS13 9333 these spurious events can occur up to roughly 6s after the policy change. Link: http://lkml.kernel.org/g/3352987.ugV1Ipy7Z5@xps13 Signed-off-by: Gabriele Mazzotta Signed-off-by: Tejun Heo [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li --- drivers/ata/libata-core.c | 15 ++++++++++++++- drivers/ata/libata-eh.c | 3 +++ include/linux/libata.h | 9 +++++++++ 3 files changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index af96831..0a6767b 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -6671,8 +6671,21 @@ u32 ata_wait_register(struct ata_port *ap, void __iomem *reg, u32 mask, u32 val, */ bool sata_lpm_ignore_phy_events(struct ata_link *link) { + unsigned long lpm_timeout = link->last_lpm_change + + msecs_to_jiffies(ATA_TMOUT_SPURIOUS_PHY); + /* if LPM is enabled, PHYRDY doesn't mean anything */ - return !!(link->lpm_policy > ATA_LPM_MAX_POWER); + if (link->lpm_policy > ATA_LPM_MAX_POWER) + return true; + + /* ignore the first PHY event after the LPM policy changed + * as it is might be spurious + */ + if ((link->flags & ATA_LFLAG_CHANGED) && + time_before(jiffies, lpm_timeout)) + return true; + + return false; } EXPORT_SYMBOL_GPL(sata_lpm_ignore_phy_events); diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 37fb4d6..033b8cd 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -3424,6 +3424,9 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy, } } + link->last_lpm_change = jiffies; + link->flags |= ATA_LFLAG_CHANGED; + return 0; fail: diff --git a/include/linux/libata.h b/include/linux/libata.h index 41608ba..35e7f71 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -182,6 +182,7 @@ enum { ATA_LFLAG_DISABLED = (1 << 6), /* link is disabled */ ATA_LFLAG_SW_ACTIVITY = (1 << 7), /* keep activity stats */ ATA_LFLAG_NO_LPM = (1 << 8), /* disable LPM on this link */ + ATA_LFLAG_CHANGED = (1 << 10), /* LPM state changed on this link */ /* struct ata_port flags */ ATA_FLAG_SLAVE_POSS = (1 << 0), /* host supports slave dev */ @@ -285,6 +286,12 @@ enum { */ ATA_TMOUT_PMP_SRST_WAIT = 5000, + /* When the LPM policy is set to ATA_LPM_MAX_POWER, there might + * be a spurious PHY event, so ignore the first PHY event that + * occurs within 10s after the policy change. + */ + ATA_TMOUT_SPURIOUS_PHY = 10000, + /* ATA bus states */ BUS_UNKNOWN = 0, BUS_DMA = 1, @@ -727,6 +734,8 @@ struct ata_link { struct ata_eh_context eh_context; struct ata_device device[ATA_MAX_DEVICES]; + + unsigned long last_lpm_change; /* when last LPM change happened */ }; #define ATA_LINK_CLEAR_BEGIN offsetof(struct ata_link, active_tag) #define ATA_LINK_CLEAR_END offsetof(struct ata_link, device[0]) -- 1.9.1