PCI: keystone: Fix link training retries initiation

BugLink: https://bugs.launchpad.net/bugs/1863588
commit 6df19872d881641e6394f93ef2938cffcbdae5bb upstream.

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index f19de60ac991b1f9fdc4d9b3054ea3962e2481e4..ea8e7ebd8c4f8b4d8b64e2de790891881f981502 100644 (file)
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -510,7 +510,7 @@ static void ks_pcie_stop_link(struct dw_pcie *pci)
        /* Disable Link training */
        val = ks_pcie_app_readl(ks_pcie, CMD_STATUS);
        val &= ~LTSSM_EN_VAL;
-       ks_pcie_app_writel(ks_pcie, CMD_STATUS, LTSSM_EN_VAL | val);
+       ks_pcie_app_writel(ks_pcie, CMD_STATUS, val);
 }
 
 static int ks_pcie_start_link(struct dw_pcie *pci)