PCI: brcmstb: Assert PERST# on BCM2711

The current PCIe driver assumes PERST# is asserted when probe() is invoked. Some older versions of the 2711/RPi bootloader left PERST# unasserted, as the Raspian OS does assert PERST# on probe(). For this reason, we assert PERST# for BCM2711 SOCs (i.e. RPi). Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jim Quinlan <[email protected]> Signed-off-by: Lorenzo Pieralisi <[email protected]>
raspberrypi · Aug 24, 2023 · 8eb8c27 · 8eb8c27
1 parent 06c2afb
commit 8eb8c27
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
@@ -874,6 +874,11 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
 
 	/* Reset the bridge */
 	pcie->bridge_sw_init_set(pcie, 1);
+
+	/* Ensure that PERST# is asserted; some bootloaders may deassert it. */
+	if (pcie->type == BCM2711)
+		pcie->perst_set(pcie, 1);
+
 	usleep_range(100, 200);
 
 	/* Take the bridge out of reset */