linux-kernel - RE: [PATCH 4.4 05/31] mfd: intel-lpss: Do not put device in reset state on suspend

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Date:   Thu, 24 Nov 2016 15:25:10 +0000
From:   "Shaikh, Azhar" <azhar.shaikh@...el.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     "stable@...r.kernel.org" <stable@...r.kernel.org>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Lee Jones <lee.jones@...aro.org>
Subject: RE: [PATCH 4.4 05/31] mfd: intel-lpss: Do not put device in reset
 state on suspend

Hi Greg,

Please pick this patch. No concerns.

Regards,
Azhar Shaikh 

-----Original Message-----
From: Greg Kroah-Hartman [mailto:gregkh@...uxfoundation.org] 
Sent: Thursday, November 24, 2016 6:55 AM
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>; stable@...r.kernel.org; Shaikh, Azhar <azhar.shaikh@...el.com>; Mika Westerberg <mika.westerberg@...ux.intel.com>; Andy Shevchenko <andriy.shevchenko@...ux.intel.com>; Lee Jones <lee.jones@...aro.org>
Subject: [PATCH 4.4 05/31] mfd: intel-lpss: Do not put device in reset state on suspend

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Azhar Shaikh <azhar.shaikh@...el.com>

commit 274e43edcda6f709aa67e436b3123e45a6270923 upstream.

Commit 41a3da2b8e163 ("mfd: intel-lpss: Save register context on
suspend") saved the register context while going to suspend and also put the device in reset state.

Due to the resetting of device, system cannot enter S3/S0ix states when no_console_suspend flag is enabled. The system and serial console both hang. The resetting of device is not needed while going to suspend. Hence remove this code.

Fixes: 41a3da2b8e163 ("mfd: intel-lpss: Save register context on suspend")
Signed-off-by: Azhar Shaikh <azhar.shaikh@...el.com>
Acked-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Signed-off-by: Lee Jones <lee.jones@...aro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/mfd/intel-lpss.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/drivers/mfd/intel-lpss.c
+++ b/drivers/mfd/intel-lpss.c
@@ -494,9 +494,6 @@ int intel_lpss_suspend(struct device *de
 	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
 		lpss->priv_ctx[i] = readl(lpss->priv + i * 4);
 
-	/* Put the device into reset state */
-	writel(0, lpss->priv + LPSS_PRIV_RESETS);
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(intel_lpss_suspend);