On 8/24/22 00:22, Marek Vasut wrote:
The MT9P006 sensor driver sporadically fails to probe because the sensor responds with a NACK condition to I2C address on the bus during an attempt to read the sensor MT9P031_CHIP_VERSION register in mt9p031_registered(). Neither the MT9P006 nor MT9P031 datasheets are clear on reset signal timing. Older MT9M034 [1] datasheet provides those timing figures in Appendix-A and indicates it is necessary to wait 850000 EXTCLK cycles before starting any I2C communication. Add such a delay, which does make the sporadic I2C NACK go away, so it is likely similar constraint applies to this sensor. [1] https://www.onsemi.com/pdf/datasheet/mt9m034-d.pdf Signed-off-by: Marek Vasut <marex@xxxxxxx> --- Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Cc: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> Cc: Stefan Riedmueller <s.riedmueller@xxxxxxxxx> --- V2: - In case clk_get_rate() returns 0, use slowest supported clock to avoid division by zero
Any news on this patch ?
