Hi, Alexander, On Thursday, February 27, 2020 2:36:57 PM EEST Alexander A Sverdlin wrote: > From: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx> > > Spansion S25FS-S family has an issue in Basic Flash Parameter Table: > DWORD-11 bits 7-4 specify write page size 512 bytes. In reality this > is configurable in the non-volatile CR3NV register and even factory > default configuration is "wrap at 256 bytes". So blind relying on BFPT > breaks write operation on these Flashes. > > All this story is vendor-specific, so add the corresponding fixup hook > which first restores the safe page size of 256 bytes from > struct flash_info but checks is more performant 512 bytes configuration > is active and adjusts the page_size accordingly. Right, clear. > > To read CR3V RDAR command is required which in turn requires addr width > and read latency to be configured, which was not the case before. Setting > these parameters is also later required for sector map selection, because: > > JESD216 allows "variable address length" and "variable latency" in > Configuration Detection Command Descriptors, in other words "as-is". > And they are still unset during Sector Map Parameter Table parsing, > which led to "map_id" determined erroneously as 0 for, e.g. S25FS128S. Please let me know I I get this right. You need to determine the addr_width and read_dummy for the RDAR command, in order to determine if the 512 page_size is active and use that instead. addr_width is not yet set because you probably are in the BFPT_DWORD1_ADDRESS_BYTES_3_OR_4 case, and as of now the case is not treated. nor->read_dummy is not set because the read operation is not yet selected. Can we safely assume that the read_dummy for the RDAR command has the same value as the read_dummy value used for all the array read commands except Read (zero latency cycles) and RSFDP (8 latency cycles)? If yes, we can determine read_dummy from BFPT and get rid of the try and error iteration. Next, we can probably use the same values at the SMPT parsing, if you hit the SMPT_CMD_ADDRESS_LEN_USE_CURRENT and SMPT_CMD_READ_DUMMY_IS_VARIABLE cases. Cheers, ta
