Tegra i2c quirks issue

[DennisTseng]

Hey,

When I insmod same camera driver on Jestson Xavier & Nano, it starting transfer data by i2c. Xavier can’t succeed but Nano work. The error message show :
" i2c i2c-31: adapter quirk: msg too long (addr 0x003d, size 4096, write) "

So I tracking what different with them, and I found that is caused by max_write_len setting in i2c-tegra.c.

static struct i2c_adapter_quirks tegra_i2c_quirks = {
.max_read_len = 4096,
.max_write_len = 4096 - 12,
};

My camera driver is on Nano i2c7: i2c@546c0000, so it setting is in i2c-tegra-vi.c.

static struct i2c_adapter_quirks tegra_i2c_quirks = {
.max_read_len = 4096,
.max_write_len = 4096,
};

Why max_write_len need to -12 in i2c-tegra.c? May I modify it would have any side effect?

[kayccc]

Sorry for the late response, our team will do the investigation and provide suggestions soon. Thanks

[ShaneCCC]

Suppose it’s WAR for t210 chip. Not sure if NX still the same. Could you modify it to try.

[DennisTseng]

I have try and it be good now.
.max_write_len = 4096 (no “- 12”) is working but just want to know between this diff will affect something else?

Thanks.