From: Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
To: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
Cc: Yao Jin <yao.jin-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Aubrey Li <aubrey.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Mika Westerberg
<mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: [PATCH 1/4] i2c: designware: No need to disable already disabled controller
Date: Thu, 15 May 2014 17:37:21 +0300 [thread overview]
Message-ID: <1400164644-3222-2-git-send-email-mika.westerberg@linux.intel.com> (raw)
In-Reply-To: <1400164644-3222-1-git-send-email-mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
If the controller is already in desired state (enabled/disabled) there is
no point in setting its state again.
Signed-off-by: Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
drivers/i2c/busses/i2c-designware-core.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index b58ecf19e767..b0792675b970 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -258,6 +258,10 @@ static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
{
int timeout = 100;
+ /* In case the controller is already in desired state */
+ if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable)
+ return;
+
do {
dw_writel(dev, enable, DW_IC_ENABLE);
if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable)
--
2.0.0.rc2
next prev parent reply other threads:[~2014-05-15 14:37 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-15 14:37 [PATCH 0/4] i2c: designware: Fixes for Asus T100 and Haswell PCI IDs Mika Westerberg
2014-05-15 14:37 ` [PATCH 2/4] i2c: designware: Disable device on system suspend Mika Westerberg
2014-05-15 14:37 ` [PATCH 4/4] i2c: designware-pci: Add Haswell PCI IDs Mika Westerberg
2014-06-06 22:44 ` [4/4] " Scot Doyle
[not found] ` <1400164644-3222-1-git-send-email-mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2014-05-15 14:37 ` Mika Westerberg [this message]
2014-06-02 16:12 ` [PATCH 1/4] i2c: designware: No need to disable already disabled controller Wolfram Sang
2014-06-02 17:34 ` Mika Westerberg
2014-06-02 17:36 ` Wolfram Sang
2014-05-15 14:37 ` [PATCH 3/4] i2c: designware: Add runtime PM hooks Mika Westerberg
2014-06-02 16:16 ` [PATCH 0/4] i2c: designware: Fixes for Asus T100 and Haswell PCI IDs Wolfram Sang
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