From 54eca60b1c94fb1de3e59a936d428a291879de8a Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Sun, 17 Jan 2021 23:06:28 +0100 Subject: [PATCH] can: length: can_fd_len2dlc(): make legnth calculation readable again 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 Link: https://lore.kernel.org/r/20210118201346.79422-1-socketcan@hartkopp.net Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- 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];