From 34f5556ddf2b5fc25696832fa4a1a7013fc80a05 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Mon, 7 Feb 2022 15:26:59 +0200 Subject: [PATCH] drm/i915: Fix dbuf slice config lookup MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 698bef8ff5d2edea5d1c9d6e5adf1bfed1e8a106 upstream. Apparently I totally fumbled the loop condition when I removed the ARRAY_SIZE() stuff from the dbuf slice config lookup. Comparing the loop index with the active_pipes bitmask is utter nonsense, what we want to do is check to see if the mask is zero or not. Note that the code actually ended up working correctly despite the fumble, up until commit eef173954432 ("drm/i915: Allow !join_mbus cases for adlp+ dbuf configuration") when things broke for real. Cc: stable@vger.kernel.org Fixes: 05e8155afe35 ("drm/i915: Use a sentinel to terminate the dbuf slice arrays") Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20220207132700.481-1-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula (cherry picked from commit a28fde308c3c1c174249ff9559b57f24e6850086) Signed-off-by: Tvrtko Ursulin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_pm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index aea4cc2b3486e..ad35e0649fb01 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4861,7 +4861,7 @@ static u8 compute_dbuf_slices(enum pipe pipe, u8 active_pipes, bool join_mbus, { int i; - for (i = 0; i < dbuf_slices[i].active_pipes; i++) { + for (i = 0; dbuf_slices[i].active_pipes != 0; i++) { if (dbuf_slices[i].active_pipes == active_pipes && dbuf_slices[i].join_mbus == join_mbus) return dbuf_slices[i].dbuf_mask[pipe];