Re: [U-Boot] [PATCH] drivers: pci: imx: add imx_pcie_remove function

On 09/22/2017 04:00 PM, David Müller (ELSOFT AG) wrote:

Hello

Does the code below really work?

On my custom MX6Q board, the code hangs on the read of the "PCIE_PL_PFLR". Please note that this code sequence is not entered the first time after a power up; I have to execute a U-Boot reset to actually trigger the hang. Any ideas what is going wrong?

MX6Q PCIe reset breakage strikes again ?

While debugging it, I also noticed the two problems below.

Tim Harvey wrote:

...

• if (is_mx6dq()) {

• u32 val, gpr1, gpr12;
  

• gpr1 = readl(&iomuxc_regs->gpr[1]);
  

• gpr12 = readl(&iomuxc_regs->gpr[12]);
  

• if ((gpr1 & IOMUXC_GPR1_PCIE_REF_CLK_EN) &&
  

•     (gpr12 & IOMUXC_GPR12_PCIE_CTL_2)) {
  

This could be (gpr12 & IOMUXC_GPR12_APPS_LTSSM_ENABLE)) {

...

• 	val = readl(MX6_DBI_ADDR + PCIE_PL_PFLR);
  

• 	val &= ~PCIE_PL_PFLR_LINK_STATE_MASK;
  

• 	val |= PCIE_PL_PFLR_FORCE_LINK;
  

• 	imx_pcie_fix_dabt_handler(true);
  

• 	writel(val, MX6_DBI_ADDR + PCIE_PL_PFLR);
  

• 	imx_pcie_fix_dabt_handler(false);
  

• 	gpr12 &= ~IOMUXC_GPR12_PCIE_CTL_2;
  

• 	writel(val, &iomuxc_regs->gpr[12]);
  

I think this should be writel(gpr12, &iomuxc_regs->gpr[12]);

or even better clrbits_le32(&iomuxc_regs->gpr[12], IOMUXC_GPR12_APPS_LTSSM_ENABLE);

as in the rest of the file.

Dave