Commit a9a73f26 authored by Devarsh Thakkar's avatar Devarsh Thakkar Committed by Tomi Valkeinen
Browse files

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: 32a1795f ("drm/tidss: New driver for TI Keystone platform Display SubSystem")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDevarsh Thakkar <devarsht@ti.com>
[Tomi: updated the desc]
Reviewed-by: default avatarJonathan Cormier <jcormier@criticallink.com>
Tested-by: default avatarJonathan Cormier <jcormier@criticallink.com>
Reviewed-by: default avatarAradhya Bhatia <aradhya.bhatia@linux.dev>
Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241021-tidss-irq-fix-v1-6-82ddaec94e4a@ideasonboard.com
parent 361a2ebb

drivers/gpu/drm/tidss/tidss_dispc.c

+4 −0
Original line number Diff line number Diff line
@@ -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);

drivers/gpu/drm/tidss/tidss_irq.c

+2 −0
Original line number Diff line number Diff line
@@ -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];