From d4185fbe2eace237b39d85e72b07f5517511b60e Mon Sep 17 00:00:00 2001
From: Mahesh Kumar <mahkumar@nvidia.com>
Date: Tue, 9 May 2023 04:40:16 +0000
Subject: [PATCH] platform: dce: add delay between ipc_notify admin-seq

Add a few microseconds delay between sending ipc-notify calls for IPC
channel reset. IPC notify ACKs are asynchronous and sending notify when
the previous ACK was still in progress will cause spurious interrupt/ACK
signal and printout FSP state warnings.

Bug 4069133

Change-Id: I20dff299149a66629dc23ab2a7cb7765eac1b4dc
Signed-off-by: Mahesh Kumar <mahkumar@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2900570
Reviewed-by: svc_kernel_abi <svc_kernel_abi@nvidia.com>
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: svc-mobile-cert <svc-mobile-cert@nvidia.com>
Reviewed-by: Vinod Atyam <vatyam@nvidia.com>
Reviewed-by: Bitan Biswas <bbiswas@nvidia.com>
Tested-by: Vinod Atyam <vatyam@nvidia.com>
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/2902404
---
 drivers/platform/tegra/dce/dce-bootstrap.c         |  1 +
 drivers/platform/tegra/dce/dce-util-common.c       | 14 ++++++++++++++
 .../platform/tegra/dce/include/dce-util-common.h   |  2 ++
 3 files changed, 17 insertions(+)

diff --git a/drivers/platform/tegra/dce/dce-bootstrap.c b/drivers/platform/tegra/dce/dce-bootstrap.c
index 02d0f910..d88fd389 100644
--- a/drivers/platform/tegra/dce/dce-bootstrap.c
+++ b/drivers/platform/tegra/dce/dce-bootstrap.c
@@ -155,6 +155,7 @@ dce_start_boot_flow(struct tegra_dce *d)
 	}
 
 	dce_admin_ivc_channel_reset(d);
+	dce_usleep_range(10, 50);
 
 	ret = dce_start_admin_seq(d);
 	if (ret) {
diff --git a/drivers/platform/tegra/dce/dce-util-common.c b/drivers/platform/tegra/dce/dce-util-common.c
index a0ad5753..436e94cc 100644
--- a/drivers/platform/tegra/dce/dce-util-common.c
+++ b/drivers/platform/tegra/dce/dce-util-common.c
@@ -601,6 +601,20 @@ unsigned long dce_get_nxt_pow_of_2(unsigned long *addr, u8 nbits)
 	return val;
 }
 
+/*
+ * dce_usleep_range : sleep between min-max range
+ *
+ * @min : minimum sleep time in usec
+ * @max : maximum sleep time in usec
+ *
+ * Return : void
+ */
+
+void dce_usleep_range(unsigned long min, unsigned long max)
+{
+	usleep_range(min, max);
+}
+
 /*
  * dce_schedule_work : schedule work in global highpri workqueue
  *
diff --git a/drivers/platform/tegra/dce/include/dce-util-common.h b/drivers/platform/tegra/dce/include/dce-util-common.h
index 03bbfe46..47c42958 100644
--- a/drivers/platform/tegra/dce/include/dce-util-common.h
+++ b/drivers/platform/tegra/dce/include/dce-util-common.h
@@ -41,6 +41,8 @@ void dce_kfree(struct tegra_dce *d, void *addr);
 
 unsigned long dce_get_nxt_pow_of_2(unsigned long *addr, u8 nbits);
 
+void dce_usleep_range(unsigned long min, unsigned long max);
+
 static inline void dce_bitmap_set(unsigned long *map,
 				  unsigned int start, unsigned int len)
 {