The mt2701_m4u_in_larb[] array contains 4 (for LARB0 to LARB3) elements, meaning mt2701_m4u_to_larb() can legitimately return 3. The current check `if (larbid >= MT2701_LARB_NR_MAX)` incorrectly rejects valid LARB3 with -EINVAL. Fix this off-by-one error by updating MT2701_LARB_NR_MAX to 4. Note that this does not cause immediate issues with the current mt2701.dtsi and mt7623n.dtsi because it only defines 3 LARBs: mediatek,larbs = <&larb0 &larb1 &larb2>; Thus, larbid never reaches 3 in the existing upstream device tree. Fixes: de78657e16f4 ("iommu/mediatek: Fix NULL pointer dereference when printing dev_name") Signed-off-by: Akari Tsuyukusa <akkun11.open@gmail.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>