We need that to adjust the len of the 2nd transfer (called data in spi-mem)
if it's too long to fit in a SPI message or SPI transfer.
Fixes: c36ff266dc82 ("spi: Extend the core to ease integration of SPI memory controllers")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Chuanhua Han <chuanhua.han@xxxxxxx>
Suggested-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
---
Changes in v5:
-Add the validation check after the op->data.nbytes assignment
-Assign the "len" variable after defining it
Changes in v4:
-Rename variable name "opcode_addr_dummy_sum" to "len".
-The comparison of "spi_max_message_size(mem->spi)" and "len" was removed.
-Adjust their order when comparing the sizes of "spi_max_message_size(mem->spi)" and "len"
-Changing the "unsigned long" type in the code to "size_t"
Changes in v3:
-Rename variable name "val" to "opcode_addr_dummy_sum".
-Place the legitimacy of the transfer size(i.e., "spi_max_message_size(mem->spi)" and
-"opcode_addr_dummy_sum") into "if (! ctlr - > mem_ops | |! ctlr-> mem_ops->exec_op) {"
structure and add "spi_max_transfer_size(mem->spi) and opcode_addr_dummy_sum".
-Adjust the formatting alignment of the code.
-"(unsigned long)op->data.nbytes" was modified to "(unsigned long)(op->data.nbytes)".
Changes in v2:
-Place the adjusted transfer bytes code in spi_mem_adjust_op_size() and check
spi_max_message_size(mem->spi) value before subtracting opcode, addr and dummy bytes.
-Change the code from fsl-espi controller to generic code(The adjustment of spi transmission
length was originally modified in the "drivers/spi/spi-fsl-espi.c" file, and now the adjustment
of transfer length is made in the "drivers/spi/spi-mem.c" file)
drivers/spi/spi-mem.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 990770d..6184fa1 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -328,10 +328,26 @@ EXPORT_SYMBOL_GPL(spi_mem_exec_op);
int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
{
struct spi_controller *ctlr = mem->spi->controller;
+ size_t len;
+
+ len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
return ctlr->mem_ops->adjust_op_size(mem, op);
+ if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
+ if (len > spi_max_transfer_size(mem->spi))
+ return -EINVAL;
+
+ op->data.nbytes = min3((size_t)(op->data.nbytes),
+ spi_max_transfer_size(mem->spi),
+ spi_max_message_size(mem->spi) -
+ len);
+
+ if (!op->data.nbytes)
+ return -EINVAL;
+ }
+
return 0;
}
EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
--
2.7.4
