Re: [PATCH v10 43/55] dt-bindings: input: atmel: support to set max bytes transferred

[Wang, Jiada]

Hi Dmitry

On 2020/04/07 23:47, Dmitry Osipenko wrote:
> 07.04.2020 12:27, Wang, Jiada ÐÐÑÐÑ:
> ..
> > > Is this a software (firmware) limitation which varies from version to
> > > version?
> >
> > the timeout issue trying to be addressed in this patch is from software,
> > one of our board a Serializer/Deserializer bridge exists between the SoC
> > (imx6) and the Atmel touch controller.
> > imx6 i2c controller driver has a timeout value(100ms) for each i2c
> > transaction,
> > Large i2c read transaction failed to complete within this timeout value
> > and therefore imx6 i2c controller driver aborts the transaction
> > and returns failure.
> >
> > Therefore this patch was created to split the large i2c transaction into
> > smaller chunks which can complete
> > within the timeout defined by i2c controller driver.
>
> Isn't it possible to use the max_read/write_len of the generic struct
> i2c_adapter_quirks for limiting the transfer size?
>
> BTW, it looks like the i.MX I2C driver doesn't specify the
> i2c_adapter_quirks, which probably needs to be fixed.
yes, i.MX I2C driver can specify i2c_adapter_quirks to limit the size be 
transferred in one transaction.

But even in this case, mxt_process_messages_t44() fails when it tries to 
transfer data count larger than max_read/write_len set in i.MX I2C 
driver, which we would like to avoid.


Thanks,
Jiada