drivers: pci: imx: fix imx_pcie_remove function
We have at least a minor count of boards, that failed to re-initialize
PCI express in the Linux kernel. Typical failure rate is 20% on affected
boards. This is mitigated by commit 6ecbe1375671 ("drivers: pci: imx:
add imx_pcie_remove function").
However, at least on some i.MX6 custom boards, when calling
assert_core_reset() as part of the first-time PCIe init, read access
to PCIE_PL_PFLR simply hangs. Surround this readl() with
imx_pcie_fix_dabt_handler() does not help. For this reason, the forced
LTSSM detection is only used on the second assert_core_reset() that is
called shorly before starting the Linux kernel.
Signed-off-by: Sven-Ola Tuecke <sven-ola.tuecke@numberfour.eu>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Tested-by: David Müller <d.mueller@elsoft.ch>
diff --git a/drivers/pci/pcie_imx.c b/drivers/pci/pcie_imx.c
index eab0a2b..2900c8d 100644
--- a/drivers/pci/pcie_imx.c
+++ b/drivers/pci/pcie_imx.c
@@ -431,7 +431,7 @@
/*
* Initial bus setup
*/
-static int imx6_pcie_assert_core_reset(void)
+static int imx6_pcie_assert_core_reset(bool prepare_for_boot)
{
struct iomuxc *iomuxc_regs = (struct iomuxc *)IOMUXC_BASE_ADDR;
@@ -459,7 +459,7 @@
* If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong
* indication that the bootloader activated the link.
*/
- if (is_mx6dq()) {
+ if (is_mx6dq() && prepare_for_boot) {
u32 val, gpr1, gpr12;
gpr1 = readl(&iomuxc_regs->gpr[1]);
@@ -605,7 +605,7 @@
uint32_t tmp;
int count = 0;
- imx6_pcie_assert_core_reset();
+ imx6_pcie_assert_core_reset(false);
imx6_pcie_init_phy();
imx6_pcie_deassert_core_reset();
@@ -687,7 +687,7 @@
void imx_pcie_remove(void)
{
- imx6_pcie_assert_core_reset();
+ imx6_pcie_assert_core_reset(true);
}
/* Probe function. */