Query: spi-nor: dummy buswidth calculation

[Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>]

Hi Boris,

I have query regarding dummy bus width calculation for the read commands, added in the patch series [1]

In func m25p80_read(), dummy.buswidth is being assigned as
+       op.dummy.buswidth = op.addr.buswidth;

Above, buswidth for dummy commands are being assigned and are marked equal to the buswidth of the address command.
This is true for case when we are doing operation in 1-4-4 or 1-2-2 protocol where data as well as address are running on same data lines and having same buswidth.

I am adding support of octal commands in framework and for this needs to add support for 1-1-8 protocol for Micron flash MT35XU512ABA1G12.
For octal command, 7Ch, flash is sending data and the dummy on the 8 data lines and address on 1 data line.

If I do below code change, then I am getting correct data else there is data corruption only in the first byte read.
-       op.dummy.buswidth = op.addr.buswidth;
+       op.dummy.buswidth = spi_nor_get_protocol_data_nbits(nor->read_proto);


[1] https://patchwork.kernel.org/patch/10334345/

--
Regards
Yogesh Gaur