From f56d9e23b78e311fbd992a1bd80b8bf2adaee29b Mon Sep 17 00:00:00 2001
From: =?utf8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
Date: Sun, 5 Apr 2015 18:39:27 +0200
Subject: [PATCH] ssb: add delay after PCI reset to fix SoC reboots
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Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
---
 drivers/ssb/driver_pcicore.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/ssb/driver_pcicore.c b/drivers/ssb/driver_pcicore.c
index d75b72ba2672..15a7ee3859dd 100644
--- a/drivers/ssb/driver_pcicore.c
+++ b/drivers/ssb/driver_pcicore.c
@@ -357,6 +357,15 @@ static void ssb_pcicore_init_hostmode(struct ssb_pcicore *pc)
 	pcicore_write32(pc, SSB_PCICORE_SBTOPCI2,
 			SSB_PCICORE_SBTOPCI_MEM | SSB_PCI_DMA);
 
+	/*
+	 * Accessing PCI config without a proper delay after devices reset (not
+	 * GPIO reset) was causing reboots on WRT300N v1.0.
+	 * Tested delay 850 us lowered reboot chance to 50-80%, 1000 us fixed it
+	 * completely. Flushing all writes was also tested but with no luck.
+	 */
+	if (pc->dev->bus->chip_id == 0x4704)
+		usleep_range(1000, 2000);
+
 	/* Enable PCI bridge BAR0 prefetch and burst */
 	val = PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
 	ssb_extpci_write_config(pc, 0, 0, 0, PCI_COMMAND, &val, 2);
-- 
2.34.1