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From: "Westerberg, Mika" <mika.westerberg-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
To: "Du, Wenkai" <wenkai.du-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: "linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>,
	"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH] i2c-designware: Mask interrupts during i2c controller enable
Date: Fri, 4 Apr 2014 21:42:32 +0300	[thread overview]
Message-ID: <20140404184232.GC19349@intel.com> (raw)
In-Reply-To: <7286EAF50D3F4E4AADE7FEECEBF8B5A537A70F8B-P5GAC/sN6hkd3b2yrw5b5LfspsVTdybXVpNB7YpNyf8@public.gmane.org>

On Fri, Apr 04, 2014 at 09:20:39PM +0300, Du, Wenkai wrote:
> In current driver implementation, I2c controller is enabled, then
> disabled every time inside i2c_dw_xfer. So I think the interrupt masking
> should be done inside i2c_dw_xfer_init, where the controller is enabled.

Interrupt masking is done already after each transaction.

The problem here is that after reset, the interrupt mask register gets
0x8ff value (HW default), which means that most of the interrupts are left
unmasked.

That is the reason why this only happens right after we resume from
system sleep. Masking interrupts on that path fixes the problem.

WARNING: multiple messages have this Message-ID (diff)
From: "Westerberg, Mika" <mika.westerberg@intel.com>
To: "Du, Wenkai" <wenkai.du@intel.com>
Cc: "linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>,
	Wolfram Sang <wsa@the-dreams.de>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] i2c-designware: Mask interrupts during i2c controller enable
Date: Fri, 4 Apr 2014 21:42:32 +0300	[thread overview]
Message-ID: <20140404184232.GC19349@intel.com> (raw)
In-Reply-To: <7286EAF50D3F4E4AADE7FEECEBF8B5A537A70F8B@ORSMSX109.amr.corp.intel.com>

On Fri, Apr 04, 2014 at 09:20:39PM +0300, Du, Wenkai wrote:
> In current driver implementation, I2c controller is enabled, then
> disabled every time inside i2c_dw_xfer. So I think the interrupt masking
> should be done inside i2c_dw_xfer_init, where the controller is enabled.

Interrupt masking is done already after each transaction.

The problem here is that after reset, the interrupt mask register gets
0x8ff value (HW default), which means that most of the interrupts are left
unmasked.

That is the reason why this only happens right after we resume from
system sleep. Masking interrupts on that path fixes the problem.

  parent reply	other threads:[~2014-04-04 18:42 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-04 17:05 [PATCH] i2c-designware: Mask interrupts during i2c controller enable Du, Wenkai
     [not found] ` <7286EAF50D3F4E4AADE7FEECEBF8B5A537A70E1F-P5GAC/sN6hkd3b2yrw5b5LfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2014-04-04 18:16   ` Westerberg, Mika
2014-04-04 18:16     ` Westerberg, Mika
     [not found]     ` <20140404181613.GB19349-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2014-04-04 18:20       ` Du, Wenkai
2014-04-04 18:20         ` Du, Wenkai
     [not found]         ` <7286EAF50D3F4E4AADE7FEECEBF8B5A537A70F8B-P5GAC/sN6hkd3b2yrw5b5LfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2014-04-04 18:42           ` Westerberg, Mika [this message]
2014-04-04 18:42             ` Westerberg, Mika
     [not found]             ` <20140404184232.GC19349-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2014-04-04 21:54               ` Du, Wenkai
2014-04-04 21:54                 ` Du, Wenkai
     [not found]                 ` <7286EAF50D3F4E4AADE7FEECEBF8B5A537A71351-P5GAC/sN6hkd3b2yrw5b5LfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2014-04-05  6:13                   ` Westerberg, Mika
2014-04-05  6:13                     ` Westerberg, Mika
     [not found]                     ` <20140405061316.GF19349-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2014-04-06 17:58                       ` One Thousand Gnomes
2014-04-06 17:58                         ` One Thousand Gnomes
     [not found]                         ` <20140406185818.3aaca03d-mUKnrFFms3BCCTY1wZZT65JpZx93mCW/@public.gmane.org>
2014-04-07  9:04                           ` Westerberg, Mika
2014-04-07  9:04                             ` Westerberg, Mika
     [not found]                             ` <20140407090403.GG19349-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2014-04-07 14:42                               ` One Thousand Gnomes
2014-04-07 14:42                                 ` One Thousand Gnomes
2014-04-07 15:11                                 ` Westerberg, Mika
     [not found]                                   ` <20140407151107.GL19349-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2014-04-07 16:48                                     ` Du, Wenkai
2014-04-07 16:48                                       ` Du, Wenkai
2014-04-08 10:30                                       ` Westerberg, Mika
2014-04-09 23:45                                         ` Du, Wenkai
2014-04-10  9:08                                           ` Westerberg, Mika
     [not found]                                             ` <20140410090826.GW19349-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2014-04-10 23:06                                               ` Du, Wenkai
2014-04-10 23:06                                                 ` Du, Wenkai

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