SPI flash: Fix alignment checks in Page Program commands
There are two separate restrictions to take into account:
Page Program command must not cross address boundaries defined by the
flash part's page size.
Total number of bytes for any command sent to flash part is restricted
by the SPI controller capabilities.
Consider
CONTROLLER_PAGE_LIMIT=64, page_size=256, offset=62, len=4.
This write would be split at offset 64 for no reason.
Consider
CONTROLLER_PAGE_LIMIT=40, page_size=256, offset=254, len=4.
This write would not be split at page boundary as required.
We do not really hit the second case. Nevertheless, CONTROLLER_PAGE_LIMIT
is a misnomer for the maximum payload length supported by the SPI controller
and is removed in a followup.
Change-Id: I727f2e7de86a91b6a509460ff1f374acd006a0bc
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/6162
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
diff --git a/src/drivers/spi/amic.c b/src/drivers/spi/amic.c
index fa17036..4cccc71 100644
--- a/src/drivers/spi/amic.c
+++ b/src/drivers/spi/amic.c
@@ -70,7 +70,7 @@
int ret;
u8 cmd[4];
- page_size = min(1 << amic->params->l2_page_size, CONTROLLER_PAGE_LIMIT);
+ page_size = 1 << amic->params->l2_page_size;
byte_addr = offset % page_size;
flash->spi->rw = SPI_WRITE_FLAG;
@@ -82,6 +82,7 @@
for (actual = 0; actual < len; actual += chunk_len) {
chunk_len = min(len - actual, page_size - byte_addr);
+ chunk_len = min(chunk_len, CONTROLLER_PAGE_LIMIT);
cmd[0] = CMD_A25_PP;
cmd[1] = (offset >> 16) & 0xff;