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 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-6.6.y git checkout FETCH_HEAD git cherry-pick -x a9a73f2661e6f625d306c9b0ef082e4593f45a21 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --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 devarsht@ti.com 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.

Fixes: 32a1795f57ee ("drm/tidss: New driver for TI Keystone platform Display SubSystem") Cc: stable@vger.kernel.org Signed-off-by: Devarsh Thakkar devarsht@ti.com [Tomi: updated the desc] Reviewed-by: Jonathan Cormier jcormier@criticallink.com Tested-by: Jonathan Cormier jcormier@criticallink.com Reviewed-by: Aradhya Bhatia aradhya.bhatia@linux.dev Signed-off-by: Tomi Valkeinen tomi.valkeinen@ideasonboard.com Link: https://patchwork.freedesktop.org/patch/msgid/20241021-tidss-irq-fix-v1-6-82...

diff --git a/drivers/gpu/drm/tidss/tidss_dispc.c b/drivers/gpu/drm/tidss/tidss_dispc.c index 515f82e8a0a5..07f5c26cfa26 100644 --- a/drivers/gpu/drm/tidss/tidss_dispc.c +++ b/drivers/gpu/drm/tidss/tidss_dispc.c @@ -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); diff --git a/drivers/gpu/drm/tidss/tidss_irq.c b/drivers/gpu/drm/tidss/tidss_irq.c index 3cc4024ec7ff..8af4682ba56b 100644 --- a/drivers/gpu/drm/tidss/tidss_irq.c +++ b/drivers/gpu/drm/tidss/tidss_irq.c @@ -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];