From b4203ce0556348dcfe29f897d1dbe65102874d89 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Wed, 15 Apr 2020 16:30:01 -0400 Subject: i3c master: GETMRL's 3rd byte is optional even with BCR_IBI_PAYLOAD According to the I3C spec v1.1 document, GETMRL's payload is 2 bytes, with an optional 3rd byte if the IBI private payload is larger than 1 byte. The whole GETMRL may also be optional so max_ibi_len already defaults to 1 if BCR_IBI_PAYLOAD prior to the i3c_master_getmrl_locked() call. Signed-off-by: Nicolas Pitre Signed-off-by: Boris Brezillon Link: https://lore.kernel.org/linux-i3c/nycvar.YSQ.7.76.2004151623060.2671@knanqh.ubzr --- drivers/i3c/master.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index d79cd6d54b3a..97f2e29265da 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -1008,7 +1008,6 @@ static int i3c_master_getmrl_locked(struct i3c_master_controller *master, struct i3c_device_info *info) { struct i3c_ccc_cmd_dest dest; - unsigned int expected_len; struct i3c_ccc_mrl *mrl; struct i3c_ccc_cmd cmd; int ret; @@ -1024,22 +1023,23 @@ static int i3c_master_getmrl_locked(struct i3c_master_controller *master, if (!(info->bcr & I3C_BCR_IBI_PAYLOAD)) dest.payload.len -= 1; - expected_len = dest.payload.len; i3c_ccc_cmd_init(&cmd, true, I3C_CCC_GETMRL, &dest, 1); ret = i3c_master_send_ccc_cmd_locked(master, &cmd); if (ret) goto out; - if (dest.payload.len != expected_len) { + switch (dest.payload.len) { + case 3: + info->max_ibi_len = mrl->ibi_len; + fallthrough; + case 2: + info->max_read_len = be16_to_cpu(mrl->read_len); + break; + default: ret = -EIO; goto out; } - info->max_read_len = be16_to_cpu(mrl->read_len); - - if (info->bcr & I3C_BCR_IBI_PAYLOAD) - info->max_ibi_len = mrl->ibi_len; - out: i3c_ccc_cmd_dest_cleanup(&dest); -- cgit v1.2.3