Improve comment about workaround ERR010727 by using official errata
document content.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/pci/controller/dwc/pci-imx6.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 6f68bee111029..6e3ac3fc33745 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -715,9 +715,25 @@ static int imx7d_pcie_core_reset(struct imx_pcie *imx_pcie, bool assert)
 		return 0;
 
 	/*
-	 * Workaround for ERR010728, failure of PCI-e PLL VCO to
-	 * oscillate, especially when cold. This turns off "Duty-cycle
-	 * Corrector" and other mysterious undocumented things.
+	 * Workaround for ERR010728 (IMX7DS_2N09P, Rev. 1.1, 4/2023):
+	 *
+	 * PCIe: PLL may fail to lock under corner conditions Initial VCO
+	 * oscillation may fail under corner conditions such as cold
+	 * temperature which will cause the PCIe PLL fail to lock in the
+	 * initialization phase.
+	 *
+	 * The Duty-cycle Corrector calibration must be disabled.
+	 *
+	 * 1. De-assert the G_RST signal by clearing
+	 *    SRC_PCIEPHY_RCR[PCIEPHY_G_RST].
+	 * 2. De-assert DCC_FB_EN by writing data “0x29” to the register
+	 *    address 0x306d0014 (PCIE_PHY_CMN_REG4).
+	 * 3. Assert RX_EQS, RX_EQ_SEL by writing data “0x48” to the register
+	 *    address 0x306d0090 (PCIE_PHY_CMN_REG24).
+	 * 4. Assert ATT_MODE by writing data “0xbc” to the register
+	 *    address 0x306d0098 (PCIE_PHY_CMN_REG26).
+	 * 5. De-assert the CMN_RST signal by clearing register bit
+	 *    SRC_PCIEPHY_RCR[PCIEPHY_BTN]
 	 */
 
 	if (likely(imx_pcie->phy_base)) {

-- 
2.34.1

On Mon, Jun 17, 2024 at 5:17 PM Frank Li <Frank.Li@nxp.com> wrote:
>
> Improve comment about workaround ERR010727 by using official errata

This should be  ERR010728, not  ERR010727.

On Mon, Jun 17, 2024 at 04:16:42PM -0400, Frank Li wrote:
> Improve comment about workaround ERR010727 by using official errata
> document content.
> 

It is useful to provide a link to the errata document in the commit message.

> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 22 +++++++++++++++++++---
>  1 file changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 6f68bee111029..6e3ac3fc33745 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -715,9 +715,25 @@ static int imx7d_pcie_core_reset(struct imx_pcie *imx_pcie, bool assert)
>  		return 0;
>  
>  	/*
> -	 * Workaround for ERR010728, failure of PCI-e PLL VCO to
> -	 * oscillate, especially when cold. This turns off "Duty-cycle
> -	 * Corrector" and other mysterious undocumented things.
> +	 * Workaround for ERR010728 (IMX7DS_2N09P, Rev. 1.1, 4/2023):
> +	 *
> +	 * PCIe: PLL may fail to lock under corner conditions Initial VCO

Missing full stop after 'conditions'?

- Mani

-- 
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