[PATCH 5.5 092/367] PCI: keystone: Fix link training retries initiation

Greg Kroah-Hartman
2020-02-10T12:51:38Z

From: Yurii Monakov <monakov.y@gmail.com>

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>

---
drivers/pci/controller/dwc/pci-keystone.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- 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_
/* 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)