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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Yurii Monakov <monakov.y@gmail.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Andrew Murray <andrew.murray@arm.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 027/116] PCI: keystone: Fix link training retries initiation
Date:   Thu, 13 Feb 2020 07:19:31 -0800
Message-Id: <20200213151853.493272633@linuxfoundation.org>
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From: Yurii Monakov <monakov.y@gmail.com>

[ Upstream commit 6df19872d881641e6394f93ef2938cffcbdae5bb ]

ks_pcie_stop_link() function does not clear LTSSM_EN_VAL bit so
link training was not triggered more than once after startup.
In configurations where link can be unstable during early boot,
for example, under low temperature, it will never be established.

Fixes: 0c4ffcfe1fbc ("PCI: keystone: Add TI Keystone PCIe driver")
Signed-off-by: Yurii Monakov <monakov.y@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Andrew Murray <andrew.murray@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/host/pci-keystone-dw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/host/pci-keystone-dw.c b/drivers/pci/host/pci-keystone-dw.c
index 9397c46671062..f011a8780ff53 100644
--- a/drivers/pci/host/pci-keystone-dw.c
+++ b/drivers/pci/host/pci-keystone-dw.c
@@ -502,7 +502,7 @@ void ks_dw_pcie_initiate_link_train(struct keystone_pcie *ks_pcie)
 	/* Disable Link training */
 	val = ks_dw_app_readl(ks_pcie, CMD_STATUS);
 	val &= ~LTSSM_EN_VAL;
-	ks_dw_app_writel(ks_pcie, CMD_STATUS, LTSSM_EN_VAL | val);
+	ks_dw_app_writel(ks_pcie, CMD_STATUS, val);
 
 	/* Initiate Link Training */
 	val = ks_dw_app_readl(ks_pcie, CMD_STATUS);
-- 
2.20.1