[U-Boot] [PATCH] drivers: pci: imx: fix imx_pcie_remove function
From: Sven-Ola Tuecke
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
Signed-off-by: Fabio Estevam
---
drivers/pci/pcie_imx.c | 8
1 file changed, 4 insertions(+), 4 deletions(-)
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 @@ static int imx_pcie_write_config(struct pci_controller
*hose, pci_dev_t d,
/*
* 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 @@ static int imx6_pcie_assert_core_reset(void)
* 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 @@ static int imx_pcie_link_up(void)
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_init(void)
void imx_pcie_remove(void)
{
- imx6_pcie_assert_core_reset();
+ imx6_pcie_assert_core_reset(true);
}
/* Probe function. */
--
2.7.4
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Re: [U-Boot] [PATCH] drivers: pci: imx: fix imx_pcie_remove function
Hi David,
On Thu, Oct 5, 2017 at 8:46 AM, Fabio Estevam wrote:
> From: Sven-Ola Tuecke
>
> 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
> Signed-off-by: Fabio Estevam
Does this patch solve the PCIE_PL_PFLR hang you reported at
https://lists.denx.de/pipermail/u-boot/2017-September/307191.html ?
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Re: [U-Boot] [PATCH] drivers: pci: imx: fix imx_pcie_remove function
Hi Fabio Fabio Estevam wrote: > From: Sven-Ola Tuecke > > However, at least on some i.MX6 custom boards, when calling By "some", I assume that not all i.MX6 systems are showing this behaviour. Does anyone have an idea which systems are affected and which are not? > 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 > Signed-off-by: Fabio Estevam Seems to work on our board therefore Tested-by: David Müller ___ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
Re: [U-Boot] [PATCH] drivers: pci: imx: fix imx_pcie_remove function
On 05/10/2017 13:46, Fabio Estevam wrote:
> From: Sven-Ola Tuecke
>
> 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
> Signed-off-by: Fabio Estevam
> ---
Applied to u-boot-imx, thanks !
Best regards,
Stefano Babic
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Re: [U-Boot] [PATCH] drivers: pci: imx: fix imx_pcie_remove function
Hi David, On Wed, Oct 11, 2017 at 5:18 AM, David Müller (ELSOFT AG) wrote: > Hi Fabio > > Fabio Estevam wrote: >> From: Sven-Ola Tuecke >> >> However, at least on some i.MX6 custom boards, when calling > > By "some", I assume that not all i.MX6 systems are showing this > behaviour. Does anyone have an idea which systems are affected and which > are not? Yes, the mx6 board I have access to do not show this issue. Not sure why it fails on your board and on Sven's. >> 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 >> Signed-off-by: Fabio Estevam > > Seems to work on our board therefore > > Tested-by: David Müller Thanks for testing and glad it works for both of you. ___ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
