linux-kernel - [PATCH V2 1/2] spmi: remove wakeup command before slave probe

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Date:	Fri, 30 Jan 2015 17:46:40 -0700
From:	Gilad Avidov <gavidov@...eaurora.org>
To:	gavidov@...eaurora.org, sdharia@...eaurora.org,
	mlocke@...eaurora.org, linux-arm-msm@...r.kernel.org,
	gregkh@...uxfoundation.org, svarbanov@...sol.com
Cc:	linux-kernel@...r.kernel.org, iivanov@...sol.com,
	galak@...eaurora.org, agross@...eaurora.org
Subject: [PATCH V2 1/2] spmi: remove wakeup command before slave probe

According to spmi spec a slave powers up into startup state and then
transitions into active state. Thus, the wakeup command is not required
before calling the slave's probe. The wakeup command is only needed for
slaves that are in sleep state after receiving the sleep command.

This is a bug since spmi master controllers, such as spmi-pmic-arb,
which have no support for wakeup command return an error on that
command and thus fail before reaching a slave driver probe.

Cc: galak@...eaurora.org
Acked-by: Sagar Dharia <sdharia@...eaurora.org>
Signed-off-by: Gilad Avidov <gavidov@...eaurora.org>
---
 drivers/spmi/spmi.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/spmi/spmi.c b/drivers/spmi/spmi.c
index 1d92f51..9ff7454 100644
--- a/drivers/spmi/spmi.c
+++ b/drivers/spmi/spmi.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -316,11 +316,6 @@ static int spmi_drv_probe(struct device *dev)
 	struct spmi_device *sdev = to_spmi_device(dev);
 	int err;
 
-	/* Ensure the slave is in ACTIVE state */
-	err = spmi_command_wakeup(sdev);
-	if (err)
-		goto fail_wakeup;
-
 	pm_runtime_get_noresume(dev);
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
@@ -335,7 +330,6 @@ fail_probe:
 	pm_runtime_disable(dev);
 	pm_runtime_set_suspended(dev);
 	pm_runtime_put_noidle(dev);
-fail_wakeup:
 	return err;
 }
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

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