Unverified Commit 52ac41b5 authored by Frank Li's avatar Frank Li Committed by Krzysztof Wilczyński
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PCI: imx6: Improve comment for workaround ERR010728 

Improve comment about workaround ERR010728 by using official errata
document content, see:

  https://www.nxp.com/webapp/Download?colCode=IMX7DS_2N09P

Link: https://lore.kernel.org/linux-pci/20240729-pci2_upstream-v8-7-b68ee5ef2b4d@nxp.com


Signed-off-by: default avatarFrank Li <Frank.Li@nxp.com>
[kwilczynski: commit log]
Signed-off-by: default avatarKrzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
parent 5223084d

drivers/pci/controller/dwc/pci-imx6.c

+20 −3
Original line number Diff line number Diff line
@@ -711,9 +711,26 @@ 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)) {