mediatek: fix PCIe #PERST being de-asserted too early

The driver for MediaTek gen3 PCIe hosts de-asserts all reset
signals at the same time using a single register write operation.
Delay the de-assertion of the #PERST signal by 100ms as some PCIe
devices fail to come up otherwise.

Sync from https://github.com/immortalwrt/immortalwrt/commit/6a2e17d5c1
This commit is contained in:
lgs2007m 2024-09-21 18:28:29 +08:00 committed by hanwckf
parent aa2041c012
commit 1b99cd51c5

View File

@ -0,0 +1,17 @@
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -317,7 +317,13 @@ static int mtk_pcie_startup_port(struct
msleep(100);
/* De-assert reset signals */
- val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB);
+ val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB);
+ writel_relaxed(val, port->base + PCIE_RST_CTRL_REG);
+
+ msleep(100);
+
+ /* De-assert PERST# signals */
+ val &= ~(PCIE_PE_RSTB);
writel_relaxed(val, port->base + PCIE_RST_CTRL_REG);
/* Check if the link is up or not */