openwrt/target/linux/bcm27xx/patches-6.1/950-0847-PCI-brcmstb-Wait-for-100ms-following-PERST-deassert.patch
Marty Jones 2e715fb4fc bcm27xx: update 6.1 patches to latest version
Add support for BCM2712 (Raspberry Pi 5).
3bb5880ab3
Patches were generated from the diff between linux kernel branch linux-6.1.y
and rpi-6.1.y from raspberry pi kernel source:
- git format-patch linux-6.1.y...rpi-6.1.y

Build system: x86_64
Build-tested: bcm2708, bcm2709, bcm2710, bcm2711
Run-tested: bcm2710/RPi3B, bcm2711/RPi4B

Signed-off-by: Marty Jones <mj8263788@gmail.com>
[Remove applied and reverted patches, squash patches and config commits]
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2024-01-25 17:46:45 +01:00

40 lines
1.5 KiB
Diff

From 6f634d7efb8876e5953c30c0a613aaa5f575fe05 Mon Sep 17 00:00:00 2001
From: Jim Quinlan <jim2101024@gmail.com>
Date: Tue, 11 Oct 2022 14:42:07 -0400
Subject: [PATCH] PCI: brcmstb: Wait for 100ms following PERST# deassert
commit 3ae140ad827b359bc4fa7c7985691c4c1e3ca8f4 upstream.
Be prudent and give some time for power and clocks to become stable. As
described in the PCIe CEM specification sections 2.2 and 2.2.1; as well as
PCIe r5.0, 6.6.1.
Link: https://lore.kernel.org/r/20221011184211.18128-3-jim2101024@gmail.com
Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
---
drivers/pci/controller/pcie-brcmstb.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -1038,8 +1038,15 @@ static int brcm_pcie_start_link(struct b
pcie->perst_set(pcie, 0);
/*
- * Give the RC/EP time to wake up, before trying to configure RC.
- * Intermittently check status for link-up, up to a total of 100ms.
+ * Wait for 100ms after PERST# deassertion; see PCIe CEM specification
+ * sections 2.2, PCIe r5.0, 6.6.1.
+ */
+ msleep(100);
+
+ /*
+ * Give the RC/EP even more time to wake up, before trying to
+ * configure RC. Intermittently check status for link-up, up to a
+ * total of 100ms.
*/
for (i = 0; i < 100 && !brcm_pcie_link_up(pcie); i += 5)
msleep(5);