openwrt/target/linux/mediatek/patches-5.15/611-pcie-mediatek-gen3-PERST-for-100ms.patch
Daniel Golle 6a2e17d5c1
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.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2023-10-03 17:38:34 +02:00

18 lines
572 B
Diff

--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -319,7 +319,13 @@ 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 */