FAILED: patch "[PATCH] drm/tidss: Fix race condition while handling interrupt" failed to apply to 6.6-stable tree

The patch below does not apply to the 6.6-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 <[email protected]>.

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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x a9a73f2661e6f625d306c9b0ef082e4593f45a21
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025021815-chrome-sycamore-9640@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From a9a73f2661e6f625d306c9b0ef082e4593f45a21 Mon Sep 17 00:00:00 2001
From: Devarsh Thakkar <[email protected]>
Date: Mon, 21 Oct 2024 17:07:50 +0300
Subject: [PATCH] drm/tidss: Fix race condition while handling interrupt
registers

The driver has a spinlock for protecting the irq_masks field and irq enable registers. However, the driver misses protecting the irq status registers which can lead to races.

Take the spinlock when accessing irqstatus too.

index 515f82e8a0a5..07f5c26cfa26 100644
@@ -2767,8 +2767,12 @@ static void dispc_init_errata(struct dispc_device *dispc)
  */
 static void dispc_softreset_k2g(struct dispc_device *dispc)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&dispc->tidss->wait_lock, flags);
 	dispc_set_irqenable(dispc, 0);
 	dispc_read_and_clear_irqstatus(dispc);
+	spin_unlock_irqrestore(&dispc->tidss->wait_lock, flags);
 
 	for (unsigned int vp_idx = 0; vp_idx < dispc->feat->num_vps; ++vp_idx)
 		VP_REG_FLD_MOD(dispc, vp_idx, DISPC_VP_CONTROL, 0, 0, 0);

index 3cc4024ec7ff..8af4682ba56b 100644
@@ -60,7 +60,9 @@ static irqreturn_t tidss_irq_handler(int irq, void *arg)
 	unsigned int id;
 	dispc_irq_t irqstatus;
 
+	spin_lock(&tidss->wait_lock);
 	irqstatus = dispc_read_and_clear_irqstatus(tidss->dispc);
+	spin_unlock(&tidss->wait_lock);
 
 	for (id = 0; id < tidss->num_crtcs; id++) {
 		struct drm_crtc *crtc = tidss->crtcs[id];