Re: [PATCH] i2c: cadence: Increase timeout per message if necessary

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On 3/22/22 5:18 PM, Michal Simek <michal.simek@xxxxxxxxxx> wrote:


On 3/22/22 16:34, tanureal@xxxxxxxxxxxxxxxxxxxxx wrote:
> On 3/21/22 3:57 PM, Michal Simek <michal.simek@xxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxxxx>
>> > ---
>> >   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@xxxxxxxxxx>
>>
>> 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.

How big is it?

M

The firmware has 33868 bytes, and it is split in a few writes. The first one to time out has 20240 bytes:

[   53.398444] cs35l41 0-0040: DSP1: Firmware version: 3
[   53.403522] cs35l41 0-0040: DSP1: cs35l41-dsp1-spk-prot.wmfw: Fri 04 Feb 2022 12:01:42 W. Europe Standard Time
[   55.331688] cdns-i2c e0004000.i2c: timeout waiting on completion
[   55.336721] cs35l41 0-0040: DSP1: cs35l41-dsp1-spk-prot.wmfw.5: Failed to write 20240 bytes at 0 in PM_PACKED: -110

20240 bytes at 100k clock should take 1.6192 seconds, which is more than the current timeout of one second.



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