HI! One more comment: On Fri, Sep 25, 2020 at 2:55 PM Ikjoon Jang <ikjn@xxxxxxxxxxxx> wrote: > +static bool mtk_nor_check_prg(const struct spi_mem_op *op) > +{ > + size_t len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes; > + > + if (len > MTK_NOR_PRG_MAX_SIZE) > + return false; > + > + if (!op->data.nbytes) > + return true; > + > + if (op->data.dir == SPI_MEM_DATA_OUT) > + return ((len + op->data.nbytes) <= MTK_NOR_PRG_MAX_SIZE); > + else if (op->data.dir == SPI_MEM_DATA_IN) > + return ((len + op->data.nbytes) <= MTK_NOR_PRG_MAX_CYCLES); You need to consider the existence of adjust_op_size in supports_op as well. This mtk_nor_check_prg still rejects SFDP reading command from spi-nor driver altogether. -- Regards, Chuanhong Guo