The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x cfa7b7659757f8d0fc4914429efa90d0d2577dd7 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025091354-plenty-unlined-c98e@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From cfa7b7659757f8d0fc4914429efa90d0d2577dd7 Mon Sep 17 00:00:00 2001 From: Jani Nikula jani.nikula@intel.com Date: Fri, 5 Sep 2025 13:41:49 +0300 Subject: [PATCH] drm/i915/power: fix size for for_each_set_bit() in abox iteration MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

for_each_set_bit() expects size to be in bits, not bytes. The abox mask iteration uses bytes, but it works by coincidence, because the local variable holding the mask is unsigned long, and the mask only ever has bit 2 as the highest bit. Using a smaller type could lead to subtle and very hard to track bugs.

Fixes: 62afef2811e4 ("drm/i915/rkl: RKL uses ABOX0 for pixel transfers") Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Matt Roper matthew.d.roper@intel.com Cc: stable@vger.kernel.org # v5.9+ Reviewed-by: Matt Roper matthew.d.roper@intel.com Link: https://lore.kernel.org/r/20250905104149.1144751-1-jani.nikula@intel.com Signed-off-by: Jani Nikula jani.nikula@intel.com (cherry picked from commit 7ea3baa6efe4bb93d11e1c0e6528b1468d7debf6) Signed-off-by: Tvrtko Ursulin tursulin@ursulin.net

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c index 273054c22325..c92f3e736228 100644 --- a/drivers/gpu/drm/i915/display/intel_display_power.c +++ b/drivers/gpu/drm/i915/display/intel_display_power.c @@ -1172,7 +1172,7 @@ static void icl_mbus_init(struct intel_display *display) if (DISPLAY_VER(display) == 12) abox_regs |= BIT(0);

- for_each_set_bit(i, &abox_regs, sizeof(abox_regs)) + for_each_set_bit(i, &abox_regs, BITS_PER_TYPE(abox_regs)) intel_de_rmw(display, MBUS_ABOX_CTL(i), mask, val); }

@@ -1629,11 +1629,11 @@ static void tgl_bw_buddy_init(struct intel_display *display) if (table[config].page_mask == 0) { drm_dbg_kms(display->drm, "Unknown memory configuration; disabling address buddy logic.\n"); - for_each_set_bit(i, &abox_mask, sizeof(abox_mask)) + for_each_set_bit(i, &abox_mask, BITS_PER_TYPE(abox_mask)) intel_de_write(display, BW_BUDDY_CTL(i), BW_BUDDY_DISABLE); } else { - for_each_set_bit(i, &abox_mask, sizeof(abox_mask)) { + for_each_set_bit(i, &abox_mask, BITS_PER_TYPE(abox_mask)) { intel_de_write(display, BW_BUDDY_PAGE_MASK(i), table[config].page_mask);