From: Jarkko Nikula <jarkko.nikula@linux.intel.com>
To: Michael Wu <michael.wu@vatics.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
Wolfram Sang <wsa@kernel.org>,
linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Morgan Chang <morgan.chang@vatics.com>
Subject: Re: [PATCH 2/2] i2c: designware: slave should do WRITE_REQUESTED before WRITE_RECEIVED
Date: Fri, 30 Oct 2020 16:46:02 +0200 [thread overview]
Message-ID: <85c6cb3f-2eeb-07c7-0a53-a502b45c91a5@linux.intel.com> (raw)
In-Reply-To: <20201030080420.28016-3-michael.wu@vatics.com>
On 10/30/20 10:04 AM, Michael Wu wrote:
> Sometimes we would get the following flow when doing an i2cset:
>
> 0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4
> I2C_SLAVE_WRITE_RECEIVED
> 0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x714 : INTR_STAT=0x204
> I2C_SLAVE_WRITE_REQUESTED
> I2C_SLAVE_WRITE_RECEIVED
>
> Documentation/i2c/slave-interface.rst says that I2C_SLAVE_WRITE_REQUESTED,
> which is mandatory, should be sent while the data did not arrive yet. It
> means in a write-request I2C_SLAVE_WRITE_REQUESTED should be reported
> before any I2C_SLAVE_WRITE_RECEIVED.
>
> By the way, I2C_SLAVE_STOP didn't be reported in the above case because
> DW_IC_INTR_STAT was not 0x200.
>
> dev->status can be used to record the current state, especially Designware
> I2C controller has no interrupts to identify a write-request. This patch
> makes not only I2C_SLAVE_WRITE_REQUESTED been reported first when
> IC_INTR_RX_FULL is rising and dev->status isn't STATUS_WRITE_IN_PROGRESS
> but also I2C_SLAVE_STOP been reported when a STOP condition is received.
>
> Signed-off-by: Michael Wu <michael.wu@vatics.com>
> ---
> drivers/i2c/busses/i2c-designware-slave.c | 45 +++++++++--------------
> 1 file changed, 18 insertions(+), 27 deletions(-)
>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
next prev parent reply other threads:[~2020-10-30 14:48 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-30 8:04 [PATCH 0/2] Designware I2C slave confusing IC_INTR_STOP_DET handle Michael Wu
2020-10-30 8:04 ` [PATCH 1/2] i2c: designware: call i2c_dw_read_clear_intrbits_slave() once Michael Wu
2020-10-30 8:04 ` [PATCH 2/2] i2c: designware: slave should do WRITE_REQUESTED before WRITE_RECEIVED Michael Wu
2020-10-30 14:46 ` Jarkko Nikula [this message]
2020-11-03 21:03 ` Wolfram Sang
2020-11-04 10:17 ` Michael.Wu
2020-11-04 10:35 ` Wolfram Sang
2020-11-04 10:51 ` Michael.Wu
2020-11-05 9:13 ` Jarkko Nikula
-- strict thread matches above, loose matches on Subject: below --
2020-10-16 6:04 [PATCH 1/2] i2c: designware: call i2c_dw_read_clear_intrbits_slave() once Michael Wu
2020-10-16 6:04 ` [PATCH 2/2] i2c: designware: slave should do WRITE_REQUESTED before WRITE_RECEIVED Michael Wu
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