From: <tanureal@opensource.cirrus.com>
To: Michal Simek <michal.simek@xilinx.com>,
Michal Simek <michal.simek@xilinx.com>,
Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-i2c@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<patches@opensource.cirrus.com>
Subject: Re: [PATCH] i2c: cadence: Increase timeout per message if necessary
Date: Tue, 22 Mar 2022 15:34:14 +0000 [thread overview]
Message-ID: <4af9c968-b837-e984-1051-2dcd240f2c08@opensource.cirrus.com> (raw)
In-Reply-To: <dd26fa4a-870e-d969-04df-1f42487e2b54@xilinx.com>
On 3/21/22 3:57 PM, Michal Simek <michal.simek@xilinx.com> wrote:
> +Shubhrajyoti
>
> On 3/9/22 10:31, Lucas Tanure wrote:
> > Timeout as 1 second sets a upper limit on the length of
> > the transfer executed, but there is no maximum length of
> > a write or read message set in i2c_adapter_quirks for this
> > controller.
>
> nit: I would expect that you have run any test and you reached an issue.
> Would be good to describe what exactly you have tried on which
> configuration to make it super clear.
>
> >
> > To remove that limitation calculate the minimal time
> > necessary, plus some wiggle room, for every message
> > and use it instead of the default one second, if
> > more than one second.
> >
> > Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
> > ---
> > drivers/i2c/busses/i2c-cadence.c | 12 ++++++++++--
> > 1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-cadence.c
> > b/drivers/i2c/busses/i2c-cadence.c
> > index 805c77143a0f..b4c1ad19cdae 100644
> > --- a/drivers/i2c/busses/i2c-cadence.c
> > +++ b/drivers/i2c/busses/i2c-cadence.c
> > @@ -760,7 +760,7 @@ static void cdns_i2c_master_reset(struct
> > i2c_adapter *adap)
> > static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg
> > *msg,
> > struct i2c_adapter *adap)
> > {
> > - unsigned long time_left;
> > + unsigned long time_left, msg_timeout;
> > u32 reg;
> > id->p_msg = msg;
> > @@ -785,8 +785,16 @@ static int cdns_i2c_process_msg(struct cdns_i2c
> > *id, struct i2c_msg *msg,
> > else
> > cdns_i2c_msend(id);
> > + /* Minimal time to execute this message */
> > + msg_timeout = msecs_to_jiffies((1000 * msg->len * BITS_PER_BYTE)
> > / id->i2c_clk);
> > + /* Plus some wiggle room */
> > + msg_timeout += msecs_to_jiffies(500);
> > +
> > + if (msg_timeout < adap->timeout)
> > + msg_timeout = adap->timeout;
> > +
> > /* Wait for the signal of completion */
> > - time_left = wait_for_completion_timeout(&id->xfer_done,
> > adap->timeout);
> > + time_left = wait_for_completion_timeout(&id->xfer_done,
> > msg_timeout);
> > if (time_left == 0) {
> > cdns_i2c_master_reset(adap);
> > dev_err(id->adap.dev.parent,
>
>
> If my assumption is right and there is any actual issue you had please
> send v2 and feel free to add there my:
> Acked-by: Michal Simek <michal.simek@xilinx.com>
>
> Thanks,
> Michal
>
>
>
The issue happens for I2C devices that have firmware, which will send a big I2C message, but the I2C controller will timeout on it.
That happened for CS35L41 DSP firmware tests, so no particular configuration, just a driver sending firmware blob over I2C.
Thanks,
Lucas
next prev parent reply other threads:[~2022-03-22 15:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-09 9:31 [PATCH] i2c: cadence: Increase timeout per message if necessary Lucas Tanure
2022-03-21 15:57 ` Michal Simek
2022-03-22 15:34 ` tanureal [this message]
2022-03-22 17:18 ` Michal Simek
2022-03-23 10:07 ` tanureal
2022-03-23 11:02 ` Michal Simek
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