Hi Pavel,
That hard coded table (spi_nor_ids - correct me if I assumed wrong) already contains support for Quad output command.
INFO("w25q16dw", 0xef6015, 0, 64 * 1024, 32,
SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
spi_nor_ids is in spi-nor-ids.c
Should I remove SPI_NOR_DUAL_READ from flags? or Did you mean other type of change?
Thanks,
Zubin