On Fri, Jan 17, 2020 at 10:26 AM Mikita Lipski <mlipski@xxxxxxx> wrote: > > > > On 1/17/20 10:09 AM, Sean Paul wrote: > > On Fri, Dec 13, 2019 at 3:09 PM <mikita.lipski@xxxxxxx> wrote: > >> > >> From: Mikita Lipski <mikita.lipski@xxxxxxx> > >> > > > > Hi Mikita, > > Unfortunately this patch causes a crash on my i915 device when I > > unplug my MST hub. The panic is below. > > Hi Sean, > > I thought this issue was fixed by Wayne Lin in > https://patchwork.freedesktop.org/patch/346736/?series=71388&rev=1 > but now I checked it seems it never got pushed. I will resend Wayne's > patch once again. > No need to resend, I can push Wayne's patch. Thanks for the pointer, Sean > Thanks > Mikita > > > > [ 38.514014] BUG: kernel NULL pointer dereference, address: 0000000000000030 > > [ 38.521801] #PF: supervisor read access in kernel mode > > [ 38.527556] #PF: error_code(0x0000) - not-present page > > [ 38.533299] PGD 0 P4D 0 > > [ 38.536127] Oops: 0000 [#1] PREEMPT SMP PTI > > [ 38.540798] CPU: 1 PID: 1324 Comm: DrmThread Not tainted > > 5.5.0-rc6-02273-g9bb4096398e7 #36 > > [ 38.550040] Hardware name: Google Fizz/Fizz, BIOS > > Google_Fizz.10139.39.0 01/04/2018 > > [ 38.558606] RIP: 0010:drm_dp_mst_atomic_check_bw_limit+0x11/0x102 > > [ 38.565418] Code: 05 ff cb bf 19 48 f7 f6 c3 0f 1f 44 00 00 55 b8 > > 0b 80 ff 0f 48 89 e5 5d c3 55 48 89 e5 41 57 41 56 41 55 41 54 4c 8d > > 77 30 53 <48> 8b 47 30 49 89 fd 49 89 f7 45 31 e4 48 8d 58 e8 48 8d 53 > > 18 4c > > [ 38.586422] RSP: 0018:ffffc9000139f9d8 EFLAGS: 00010282 > > [ 38.592264] RAX: 0000000000000000 RBX: ffff888272aeac88 RCX: ffff888236f529e0 > > [ 38.600242] RDX: ffff888272aeac88 RSI: ffff888236f529e0 RDI: 0000000000000000 > > [ 38.608220] RBP: ffffc9000139fa00 R08: 0000000000000031 R09: 000000000000000e > > [ 38.616198] R10: ffff888236f529e8 R11: ffff8882621f3440 R12: 0000000000000000 > > [ 38.624176] R13: ffff888236f529d0 R14: 0000000000000030 R15: ffff888236f529e0 > > [ 38.632153] FS: 00007cd9229ce700(0000) GS:ffff888276c80000(0000) > > knlGS:0000000000000000 > > [ 38.641193] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 38.647616] CR2: 0000000000000030 CR3: 00000002618e8004 CR4: 00000000003606e0 > > [ 38.655593] Call Trace: > > [ 38.658329] drm_dp_mst_atomic_check+0x152/0x16d > > [ 38.663484] intel_atomic_check+0xcfe/0x1e6f > > [ 38.668259] ? trace_hardirqs_on+0x28/0x3d > > [ 38.672835] ? intel_pipe_config_compare+0x1b38/0x1b38 > > [ 38.678580] drm_atomic_check_only+0x5ab/0x70f > > [ 38.683547] ? drm_atomic_set_crtc_for_connector+0xf5/0x102 > > [ 38.689778] ? drm_atomic_helper_shutdown+0xb6/0xb6 > > [ 38.695221] drm_atomic_commit+0x18/0x53 > > [ 38.699604] drm_atomic_helper_set_config+0x5a/0x70 > > [ 38.705057] drm_mode_setcrtc+0x2ab/0x833 > > [ 38.709537] ? rcu_read_unlock+0x57/0x57 > > [ 38.713920] ? drm_mode_getcrtc+0x173/0x173 > > [ 38.718594] drm_ioctl+0x2e5/0x424 > > [ 38.722392] ? drm_mode_getcrtc+0x173/0x173 > > [ 38.727069] vfs_ioctl+0x21/0x2f > > [ 38.730675] do_vfs_ioctl+0x5fb/0x61e > > [ 38.734766] ksys_ioctl+0x55/0x75 > > [ 38.738469] __x64_sys_ioctl+0x1a/0x1e > > [ 38.742659] do_syscall_64+0x5c/0x6d > > [ 38.746653] entry_SYSCALL_64_after_hwframe+0x49/0xbe > > [ 38.752298] RIP: 0033:0x7cd92552d497 > > [ 38.756291] Code: 8a 66 90 48 8b 05 d1 d9 2b 00 64 c7 00 26 00 00 > > 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 > > 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d9 2b 00 f7 d8 64 89 > > 01 48 > > [ 38.777296] RSP: 002b:00007cd9229cd698 EFLAGS: 00000246 ORIG_RAX: > > 0000000000000010 > > [ 38.785762] RAX: ffffffffffffffda RBX: 000020323373da80 RCX: 00007cd92552d497 > > [ 38.793740] RDX: 00007cd9229cd6d0 RSI: 00000000c06864a2 RDI: 000000000000001c > > [ 38.801717] RBP: 00007cd9229cd6c0 R08: 0000000000000000 R09: 0000000000000000 > > [ 38.809693] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000001c > > [ 38.817670] R13: 0000000000000000 R14: 00007cd9229cd6d0 R15: 00000000c06864a2 > > [ 38.825642] Modules linked in: xt_nat cdc_ether r8152 bridge stp > > llc usbhid btusb btrtl btbcm btintel bluetooth asix usbnet > > ecdh_generic ecc mii snd_soc_hdac_hdmi snd_soc_dmic xhci_pci xhci_hcd > > snd_soc_skl snd_soc_sst_ipc snd_soc_sst_dsp snd_hda_ext_core > > snd_intel_dspcfg snd_hda_core usbcore usb_common acpi_als kfifo_buf > > industrialio xt_MASQUERADE iptable_nat nf_nat xt_mark fuse > > ip6table_filter iwlmvm mac80211 r8169 realtek iwlwifi lzo_rle > > lzo_compress zram cfg80211 > > [ 38.871839] CR2: 0000000000000030 > > [ 38.875542] ---[ end trace 6bb39ec52e30c7cb ]--- > > [ 38.886142] RIP: 0010:drm_dp_mst_atomic_check_bw_limit+0x11/0x102 > > [ 38.892957] Code: 05 ff cb bf 19 48 f7 f6 c3 0f 1f 44 00 00 55 b8 > > 0b 80 ff 0f 48 89 e5 5d c3 55 48 89 e5 41 57 41 56 41 55 41 54 4c 8d > > 77 30 53 <48> 8b 47 30 49 89 fd 49 89 f7 45 31 e4 48 8d 58 e8 48 8d 53 > > 18 4c > > [ 38.913964] RSP: 0018:ffffc9000139f9d8 EFLAGS: 00010282 > > [ 38.919804] RAX: 0000000000000000 RBX: ffff888272aeac88 RCX: ffff888236f529e0 > > [ 38.927784] RDX: ffff888272aeac88 RSI: ffff888236f529e0 RDI: 0000000000000000 > > [ 38.935765] RBP: ffffc9000139fa00 R08: 0000000000000031 R09: 000000000000000e > > [ 38.943733] R10: ffff888236f529e8 R11: ffff8882621f3440 R12: 0000000000000000 > > [ 38.951712] R13: ffff888236f529d0 R14: 0000000000000030 R15: ffff888236f529e0 > > [ 38.959692] FS: 00007cd9229ce700(0000) GS:ffff888276c80000(0000) > > knlGS:0000000000000000 > > [ 38.968730] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 38.975144] CR2: 0000000000000030 CR3: 00000002618e8004 CR4: 00000000003606e0 > > [ 38.983121] Kernel panic - not syncing: Fatal exception > > [ 38.988967] Kernel Offset: disabled > > [ 38.998280] ---[ end Kernel panic - not syncing: Fatal exception ]--- > > > > > > > > > > > > > >> [why] > >> Adding PBN attribute to drm_dp_vcpi_allocation structure to > >> keep track of how much bandwidth each Port requires. > >> Adding drm_dp_mst_atomic_check_bw_limit to verify that > >> state's bandwidth needs doesn't exceed available bandwidth. > >> The funtion is called in drm_dp_mst_atomic_check after > >> drm_dp_mst_atomic_check_topology_state to fully verify that > >> the proposed topology is supported. > >> > >> v2: Fixing some typos and indentations > >> > >> Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx> > >> Signed-off-by: Mikita Lipski <mikita.lipski@xxxxxxx> > >> --- > >> drivers/gpu/drm/drm_dp_mst_topology.c | 66 ++++++++++++++++++++++++++- > >> include/drm/drm_dp_mst_helper.h | 1 + > >> 2 files changed, 65 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c > >> index 7cd505e771ff..f8b72ac79c66 100644 > >> --- a/drivers/gpu/drm/drm_dp_mst_topology.c > >> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c > >> @@ -4052,7 +4052,7 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, > >> { > >> struct drm_dp_mst_topology_state *topology_state; > >> struct drm_dp_vcpi_allocation *pos, *vcpi = NULL; > >> - int prev_slots, req_slots; > >> + int prev_slots, prev_bw, req_slots; > >> > >> topology_state = drm_atomic_get_mst_topology_state(state, mgr); > >> if (IS_ERR(topology_state)) > >> @@ -4063,6 +4063,7 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, > >> if (pos->port == port) { > >> vcpi = pos; > >> prev_slots = vcpi->vcpi; > >> + prev_bw = vcpi->pbn; > >> > >> /* > >> * This should never happen, unless the driver tries > >> @@ -4078,8 +4079,10 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, > >> break; > >> } > >> } > >> - if (!vcpi) > >> + if (!vcpi) { > >> prev_slots = 0; > >> + prev_bw = 0; > >> + } > >> > >> if (pbn_div <= 0) > >> pbn_div = mgr->pbn_div; > >> @@ -4089,6 +4092,9 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, > >> DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n", > >> port->connector->base.id, port->connector->name, > >> port, prev_slots, req_slots); > >> + DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n", > >> + port->connector->base.id, port->connector->name, > >> + port, prev_bw, pbn); > >> > >> /* Add the new allocation to the state */ > >> if (!vcpi) { > >> @@ -4101,6 +4107,7 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, > >> list_add(&vcpi->next, &topology_state->vcpis); > >> } > >> vcpi->vcpi = req_slots; > >> + vcpi->pbn = pbn; > >> > >> return req_slots; > >> } > >> @@ -4677,6 +4684,58 @@ static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, > >> kfree(mst_state); > >> } > >> > >> +static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, > >> + struct drm_dp_mst_branch *branch) > >> +{ > >> + while (port->parent) { > >> + if (port->parent == branch) > >> + return true; > >> + > >> + if (port->parent->port_parent) > >> + port = port->parent->port_parent; > >> + else > >> + break; > >> + } > >> + return false; > >> +} > >> + > >> +static inline > >> +int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch, > >> + struct drm_dp_mst_topology_state *mst_state) > >> +{ > >> + struct drm_dp_mst_port *port; > >> + struct drm_dp_vcpi_allocation *vcpi; > >> + int pbn_limit = 0, pbn_used = 0; > >> + > >> + list_for_each_entry(port, &branch->ports, next) { > >> + if (port->mstb) > >> + if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state)) > >> + return -EINVAL; > >> + > >> + if (port->available_pbn > 0) > >> + pbn_limit = port->available_pbn; > >> + } > >> + DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch has %d PBN available\n", > >> + branch, pbn_limit); > >> + > >> + list_for_each_entry(vcpi, &mst_state->vcpis, next) { > >> + if (!vcpi->pbn) > >> + continue; > >> + > >> + if (drm_dp_mst_port_downstream_of_branch(vcpi->port, branch)) > >> + pbn_used += vcpi->pbn; > >> + } > >> + DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch used %d PBN\n", > >> + branch, pbn_used); > >> + > >> + if (pbn_used > pbn_limit) { > >> + DRM_DEBUG_ATOMIC("[MST BRANCH:%p] No available bandwidth\n", > >> + branch); > >> + return -EINVAL; > >> + } > >> + return 0; > >> +} > >> + > >> static inline int > >> drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr, > >> struct drm_dp_mst_topology_state *mst_state) > >> @@ -4808,6 +4867,9 @@ int drm_dp_mst_atomic_check(struct drm_atomic_state *state) > >> ret = drm_dp_mst_atomic_check_topology_state(mgr, mst_state); > >> if (ret) > >> break; > >> + ret = drm_dp_mst_atomic_check_bw_limit(mgr->mst_primary, mst_state); > >> + if (ret) > >> + break; > >> } > >> > >> return ret; > >> diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h > >> index 830c94b7f45d..2919d9776af3 100644 > >> --- a/include/drm/drm_dp_mst_helper.h > >> +++ b/include/drm/drm_dp_mst_helper.h > >> @@ -502,6 +502,7 @@ struct drm_dp_payload { > >> struct drm_dp_vcpi_allocation { > >> struct drm_dp_mst_port *port; > >> int vcpi; > >> + int pbn; > >> bool dsc_enabled; > >> struct list_head next; > >> }; > >> -- > >> 2.17.1 > >> > >> _______________________________________________ > >> dri-devel mailing list > >> dri-devel@xxxxxxxxxxxxxxxxxxxxx > >> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&data=02%7C01%7Cmikita.lipski%40amd.com%7C2b736cb4c0f1456691ec08d79b5f4c69%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637148705931074877&sdata=s4q0ni0H%2FiPgonlMMK9Od7UK5M%2FC%2F0rsQEGsr1FP0XU%3D&reserved=0 > > -- > Thanks, > Mikita Lipski > Software Engineer 2, AMD > mikita.lipski@xxxxxxx _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
