In commit 652562e5ff06 ("can: length: can_fd_len2dlc(): simplify length calculcation") the readability of the code degraded and became more error prone. To counteract this, partially convert that patch and replace open coded values (of the original code) with proper defines. Fixes: 652562e5ff06 ("can: length: can_fd_len2dlc(): simplify length calculcation") Cc: Vincent MAILHOL <mailhol.vincent@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210118201346.79422-1-socketcan@xxxxxxxxxxxx Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/dev/length.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/dev/length.c b/drivers/net/can/dev/length.c index d35c4e82314d..b48140b1102e 100644 --- a/drivers/net/can/dev/length.c +++ b/drivers/net/can/dev/length.c @@ -27,12 +27,17 @@ static const u8 len2dlc[] = { 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */ 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */ 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */ + 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */ + 15, 15, 15, 15, 15, 15, 15, 15 /* 57 - 64 */ }; /* map the sanitized data length to an appropriate data length code */ u8 can_fd_len2dlc(u8 len) { - if (len >= ARRAY_SIZE(len2dlc)) + /* check for length mapping table size at build time */ + BUILD_BUG_ON(ARRAY_SIZE(len2dlc) != CANFD_MAX_DLEN + 1); + + if (unlikely(len > CANFD_MAX_DLEN)) return CANFD_MAX_DLC; return len2dlc[len]; -- 2.29.2