850-v5.17-0009-PCI-aardvark-Assert-PERST-when-unbinding-driver.patch

From 1f54391be8ce0c981d312cb93acdc5608def576a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Tue, 30 Nov 2021 18:29:11 +0100
Subject: [PATCH] PCI: aardvark: Assert PERST# when unbinding driver
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Put the PCIe card into reset by asserting PERST# signal when unbinding
driver. It doesn't make sense to leave the card working if it can't
communicate with the host. This should also save some power.

Link: https://lore.kernel.org/r/20211130172913.9727-10-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 drivers/pci/controller/pci-aardvark.c | 4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -1725,6 +1725,10 @@ static int advk_pcie_remove(struct platf
 	/* Free config space for emulated root bridge */
 	pci_bridge_emul_cleanup(&pcie->bridge);
 
+	/* Assert PERST# signal which prepares PCIe card for power down */
+	if (pcie->reset_gpio)
+		gpiod_set_value_cansleep(pcie->reset_gpio, 1);
+
 	/* Disable outbound address windows mapping */
 	for (i = 0; i < OB_WIN_COUNT; i++)
 		advk_pcie_disable_ob_win(pcie, i);