60c9c9b03f00622f6fa57b0a2276c6b181786fb3
[openwrt/staging/lynxis.git] /
1 From d6baa1bd90e7e68ac69d5378d70174ea67bf35dc Mon Sep 17 00:00:00 2001
2 From: James Hughes <james.hughes@raspberrypi.org>
3 Date: Mon, 29 Jul 2019 12:02:59 +0100
4 Subject: [PATCH] Fixup FKMS interrupt handing for non-existent display
5
6 If an errant interrupt flag was received from a non-existent display,
7 a NULL pointer access was made. Protect against this by checking if a
8 second display is present prior to checking the interrupt flags.
9 ---
10 drivers/gpu/drm/vc4/vc4_firmware_kms.c | 17 ++++++++++-------
11 1 file changed, 10 insertions(+), 7 deletions(-)
12
13 --- a/drivers/gpu/drm/vc4/vc4_firmware_kms.c
14 +++ b/drivers/gpu/drm/vc4/vc4_firmware_kms.c
15 @@ -1087,14 +1087,17 @@ static irqreturn_t vc4_crtc_irq_handler(
16 vc4_crtc_handle_page_flip(crtc_list[0]);
17 }
18
19 - /* Check for the secondary display too */
20 - chan = readl(crtc_list[0]->regs + SMIDSW1);
21 + if (crtc_list[1]) {
22 + /* Check for the secondary display too */
23 + chan = readl(crtc_list[0]->regs + SMIDSW1);
24
25 - if (chan & 1) {
26 - writel(SMI_NEW, crtc_list[0]->regs + SMIDSW1);
27 - if (crtc_list[1]->vblank_enabled)
28 - drm_crtc_handle_vblank(&crtc_list[1]->base);
29 - vc4_crtc_handle_page_flip(crtc_list[1]);
30 + if (chan & 1) {
31 + writel(SMI_NEW, crtc_list[0]->regs + SMIDSW1);
32 +
33 + if (crtc_list[1]->vblank_enabled)
34 + drm_crtc_handle_vblank(&crtc_list[1]->base);
35 + vc4_crtc_handle_page_flip(crtc_list[1]);
36 + }
37 }
38 }
39