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.
