In the ABI header, GUC_CTB_MSG_MIN_LEN is '1' because GUC_CTB_HDR_LEN is 1. This aligns with H2G/G2H CTB specification where all command formats are defined in units of dwords so that '1' is a dword. Accordingly, GUC_CTB_MSG_MAX_LEN is 256-1 (i.e. 255 dwords). However, h2g_write was incorrectly assuming that GUC_CTB_MSG_MAX_LEN was in bytes. Fix this. Signed-off-by: Alan Previn <alan.previn.teres.alexis@xxxxxxxxx> --- drivers/gpu/drm/xe/xe_guc_ct.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c index 137c184df487..8e9df6052b02 100644 --- a/drivers/gpu/drm/xe/xe_guc_ct.c +++ b/drivers/gpu/drm/xe/xe_guc_ct.c @@ -401,7 +401,7 @@ static int h2g_write(struct xe_guc_ct *ct, const u32 *action, u32 len, { struct xe_device *xe = ct_to_xe(ct); struct guc_ctb *h2g = &ct->ctbs.h2g; - u32 cmd[GUC_CTB_MSG_MAX_LEN / sizeof(u32)]; + u32 cmd[GUC_CTB_MSG_MAX_LEN]; u32 cmd_len = len + GUC_CTB_HDR_LEN; u32 cmd_idx = 0, i; u32 tail = h2g->info.tail; @@ -409,7 +409,7 @@ static int h2g_write(struct xe_guc_ct *ct, const u32 *action, u32 len, tail * sizeof(u32)); lockdep_assert_held(&ct->lock); - XE_BUG_ON(len * sizeof(u32) > GUC_CTB_MSG_MAX_LEN); + XE_BUG_ON(len > GUC_CTB_MSG_MAX_LEN - 1); XE_BUG_ON(tail > h2g->info.size); /* Command will wrap, zero fill (NOPs), return and check credits again */ base-commit: 9f49c413b187c00f223eaf1e8dbe2c1a97c9954b -- 2.39.0