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-rw-r--r--drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
index 217510c12af5..211edd9ef0c9 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
@@ -334,10 +334,12 @@ mcp251xfd_regmap_crc_read(void *context,
* register. It increments once per SYS clock tick,
* which is 20 or 40 MHz.
*
- * Observation shows that if the lowest byte (which is
- * transferred first on the SPI bus) of that register
- * is 0x00 or 0x80 the calculated CRC doesn't always
- * match the transferred one.
+ * Observation on the mcp2518fd shows that if the
+ * lowest byte (which is transferred first on the SPI
+ * bus) of that register is 0x00 or 0x80 the
+ * calculated CRC doesn't always match the transferred
+ * one. On the mcp2517fd this problem is not limited
+ * to the first byte being 0x00 or 0x80.
*
* If the highest bit in the lowest byte is flipped
* the transferred CRC matches the calculated one. We
@@ -346,7 +348,8 @@ mcp251xfd_regmap_crc_read(void *context,
* correct.
*/
if (reg == MCP251XFD_REG_TBC &&
- (buf_rx->data[0] == 0x0 || buf_rx->data[0] == 0x80)) {
+ ((buf_rx->data[0] & 0xf8) == 0x0 ||
+ (buf_rx->data[0] & 0xf8) == 0x80)) {
/* Flip highest bit in lowest byte of le32 */
buf_rx->data[0] ^= 0x80;