Repository navigation
drm/panel: waveshare: Add automatic panel recognition for DSI panels - #3
Merged
EngineerWill merged 2 commits intoAug 13, 2026
Merged
Conversation
Add support for Waveshare automatic recognition DSI panels which identify themselves at runtime via I2C registers. The driver reads screen type, rotation and refresh rate from registers 0xd0-0xd3 to select the appropriate display mode and DSI lane configuration. Supported configurations include 1200x1920 and 1920x1200 panels at both 30fps (2 lanes) and 60fps (4 lanes) refresh rates. Signed-off-by: Engineer_Will <646689853@qq.com>
Add the auto_rec overlay parameter to select the automatic recognition panel compatible string (waveshare,automatic-recognition-panel). This enables runtime panel detection via I2C for Waveshare DSI displays that support automatic identification. Use lowercase with underscores for the parameter name to follow kernel naming conventions. Signed-off-by: Engineer_Will <646689853@qq.com>
EngineerWill
force-pushed
the
waveshare-dsi
branch
from
August 13, 2026 08:56
765af07 to
42e7f15
Compare
EngineerWill
pushed a commit
that referenced
this pull request
Oct 15, 2026
[ Upstream commit d85f0f0 ] A write command whose data is sent entirely as immediate data is not registered. iser_reg_mem_fastreg() takes the DMA key path and leaves rdma_reg[ISER_DIR_OUT].desc at NULL, while iser_dma_map_task_data() has already set dir[ISER_DIR_OUT]. iser_check_remote_inv() looks at dir[] alone and hands the descriptor to iser_inv_desc(), which reads desc->sig_protected. A target that answers such a command with IB_WR_SEND_WITH_INV faults the initiator. Leaving those commands unregistered is deliberate. The same function already terminates the connection when a target sends a remote invalidation the initiator did not ask for. A target that invalidates a direction that was never registered is in the same class, so give it the same answer. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 0 UID: 0 PID: 40 Comm: kworker/u8:2 Not tainted 7.2.0-rc5-ISERHOST-gf5098b6bae76-dirty #3 PREEMPT(lazy) Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: rxe_wq do_work RIP: 0010:iser_task_rsp+0x6d6/0xec0 Code: 48 c1 ea 03 80 3c 02 00 0f 85 ba 06 00 00 48 8b 9b 78 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 20 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 76 06 00 00 80 7b 20 00 0f 84 3d 04 RSP: 0018:ffff88811b008db8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000001848 RDX: 0000000000000004 RSI: 1ffff11021587b12 RDI: 0000000000000020 RBP: ffff88810adc1ae4 R08: ffff888109b7f860 R09: ffffffff90a922c0 R10: ffff88810adc1a1c R11: 000000000000003c R12: ffff888109b7f800 R13: ffff88810adc1acc R14: ffff888109b7f820 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88818a676000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000005afe2b CR3: 000000010af23005 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <IRQ> __ib_process_cq+0xe1/0x390 ib_poll_handler+0x6e/0x200 irq_poll_softirq+0x1df/0x480 ? clockevents_program_event+0x2ba/0x860 ? __pfx_irq_poll_softirq+0x10/0x10 handle_softirqs+0x18e/0x590 ? __pfx_handle_softirqs+0x10/0x10 ? __hrtimer_rearm_deferred+0x156/0x450 do_softirq+0x3b/0x60 </IRQ> <TASK> __local_bh_enable_ip+0x61/0x70 __alloc_skb+0x732/0x890 ? _raw_spin_lock_irqsave+0x85/0xe0 ? __pfx___alloc_skb+0x10/0x10 ? _raw_read_unlock_irqrestore+0x16/0x50 rxe_init_packet+0x16b/0x4f0 prepare_ack_packet+0xb8/0x830 rxe_receiver+0x499/0x9980 ? __pfx_rxe_receiver+0x10/0x10 ? rxe_completer+0x29e5/0x38c0 ? hrtimer_start_range_ns_common+0x75f/0x1730 ? hrtimer_start_range_ns+0xa6/0x2c0 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? __pfx_rxe_receiver+0x10/0x10 do_work+0x144/0x470 process_one_work+0x633/0x1030 ? assign_work+0x11d/0x370 worker_thread+0x45b/0xd10 ? __pfx_worker_thread+0x10/0x10 kthread+0x2c6/0x3b0 ? recalc_sigpending+0x15c/0x1e0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x36e/0x5a0 ? __pfx_ret_from_fork+0x10/0x10 ? __switch_to+0x572/0xdd0 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- Fixes: 59caaed ("IB/iser: Support the remote invalidation exception") Signed-off-by: Yehyeong Lee <yhlee@isslab.korea.ac.kr> Link: https://patch.msgid.link/20260819010804.641772-1-yhlee@isslab.korea.ac.kr Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Signed-off-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
EngineerWill
pushed a commit
that referenced
this pull request
Oct 21, 2026
…zapped [ Upstream commit d1a3c21 ] Wire up a gmem_invalidate_range() call for SNP VMs, and use it to force vCPUs to reload/recheck their guest-provided VMSA if the backing gmem page is being invalidated, e.g. is being PUNCH_HOLE'd. Use the same core logic to handle invalidations as VMX does for the APIC-access page, as the two concepts are nearly identical: shove the physical address of a page into the vCPU's control structure: 1. Snapshot the invalidation sequence counter 2. Grab the pfn (from guest_memfd in this case) 3. Acquire mmu_lock for read 4. Re-request reload if retry is needed, otherwise commit the change. Note, the re-request action in #4 is necessary as KVM's retry logic is fuzzy, i.e. can get false positives. If the guest_memfd page has been dropped, at some point a subsequent reload will fail to get a PFN from guest_memfd, and KVM will fail KVM_RUN. If the retry was due to a false positive, KVM will retry until there are no relevant MMU notifier events (and will retry in the "outer" loop, i.e. will drop locks and resched as needed). Note #2! Take care to invalidate the VMSA when a relevant memslot is DELETED or MOVED, as invalidations in response to PUNCH_HOLE are predicated on memslot bindings (KVM doesn't know what GFN range(s) to invalidate without a binding). And more importantly, the VMSA mapping requires a memslot, i.e. must be invalidated if its memslots disappears, regardless of the state of the underlying guest_memfd inode. Failure to invalidate the vCPU's control.vmsa_pa (which is checked by pre_sev_run()) can prevent KVM from properly freeing the page as firmware will reject the RMPUPDATE to reclaim the page with FAIL_INUSE if the vCPU is actively running, i.e. if VMSA page is in-use. That in turn leads to an RMP #PF on the next use, as the page will still be assigned to the SNP VM. SEV-SNP: RMPUPDATE failed for PFN 78d198, pg_level: 1, ret: 3 SEV-SNP: PFN 0x78d198, RMP entry: [0xfff0000000144001 - 0x000000000000000f] CPU: 3 UID: 0 PID: 31345 Comm: sev_snp_vmsa_pu Tainted: G U O Tainted: [U]=USER, [O]=OOT_MODULE Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.86.0-102 01/25/2026 Call Trace: <TASK> dump_stack_lvl+0x54/0x70 rmpupdate+0x12c/0x140 rmp_make_shared+0x3b/0x60 sev_gmem_invalidate+0xe0/0x170 [kvm_amd] delete_from_page_cache_batch+0x1d8/0x220 truncate_inode_pages_range+0x120/0x3d0 kvm_gmem_fallocate+0x19a/0x270 [kvm] vfs_fallocate+0x1bc/0x1f0 __x64_sys_fallocate+0x48/0x70 do_syscall_64+0x10a/0x480 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x496c7e </TASK> ------------[ cut here ]------------ SEV: Failed to update RMP entry for PFN 0x78d198 error -14 WARNING: arch/x86/kvm/svm/sev.c:5160 at sev_gmem_invalidate+0x126/0x170 [kvm_amd], CPU#3: sev_snp_vmsa_pu/31345 CPU: 3 UID: 0 PID: 31345 Comm: sev_snp_vmsa_pu Tainted: G U O Tainted: [U]=USER, [O]=OOT_MODULE Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.86.0-102 01/25/2026 RIP: 0010:sev_gmem_invalidate+0x12b/0x170 [kvm_amd] Call Trace: <TASK> delete_from_page_cache_batch+0x1d8/0x220 truncate_inode_pages_range+0x120/0x3d0 kvm_gmem_fallocate+0x19a/0x270 [kvm] vfs_fallocate+0x1bc/0x1f0 __x64_sys_fallocate+0x48/0x70 do_syscall_64+0x10a/0x480 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x496c7e </TASK> irq event stamp: 20689 hardirqs last enabled at (20699): [<ffffffff8e76092c>] __console_unlock+0x5c/0x60 hardirqs last disabled at (20708): [<ffffffff8e760911>] __console_unlock+0x41/0x60 softirqs last enabled at (20722): [<ffffffff8e6cd74e>] __irq_exit_rcu+0x7e/0x140 softirqs last disabled at (20717): [<ffffffff8e6cd74e>] __irq_exit_rcu+0x7e/0x140 ---[ end trace 0000000000000000 ]--- BUG: unable to handle page fault for address: ffff99a64d198000 #PF: supervisor write access in kernel mode #PF: error_code(0x80000003) - RMP violation PGD 13eb001067 P4D 13eb001067 PUD 78d1d1063 PMD 1184e0063 PTE 800000078d198163 SEV-SNP: PFN 0x78d198, RMP entry: [0x6030000000144001 - 0x000000000000000f] Oops: Oops: 0003 [#1] SMP CPU: 3 UID: 0 PID: 31407 Comm: highlanderd_hea Tainted: G U W O Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 34.86.0-102 01/25/2026 RIP: 0010:prep_new_page+0x67/0x220 Call Trace: <TASK> get_page_from_freelist+0x1c40/0x1c70 __alloc_frozen_pages_noprof+0xca/0x1f0 alloc_pages_mpol+0x10b/0x1b0 alloc_pages_noprof+0x81/0x90 pte_alloc_one+0x1b/0xd0 do_pte_missing+0xdf/0x1020 handle_mm_fault+0x7c7/0xb20 do_user_addr_fault+0x268/0x6b0 exc_page_fault+0x67/0xa0 asm_exc_page_fault+0x26/0x30 RIP: 0033:0x4a6b1e </TASK> gsmi: Log Shutdown Reason 0x03 CR2: ffff99a64d198000 ---[ end trace 0000000000000000 ]--- RIP: 0010:prep_new_page+0x67/0x220 Drop the pseudo-TODO comment about needing to pin the page if guest_memfd every supports migration, as integrating with invalidations events means KVM will Just Work if/when page migration is ever supported (assuming SNP hardware supports migrating VMSA pages). Note #3, invalidate() and invalidate_range() have _completely_ different semantics; the new invalidate_range() is a true invalidation, whereas the existing invalidate() is really a "make shared" operation. Ignore the confusing naming and poor Kconfig bundling for the moment to minimize the delta for LTS kernels, the mess will be cleaned up shortly. Reported-by: Hyunwoo Kim <imv4bel@gmail.com> Closes: https://lore.kernel.org/all/aimMWzAf5b3luM0b@v4bel Fixes: e366f92 ("KVM: SEV: Support SEV-SNP AP Creation NAE event") Cc: stable@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Michael Roth <michael.roth@amd.com> Cc: Jörg Rödel <joro@8bytes.org> Cc: Fuad Tabba <tabba@google.com> Cc: Ackerley Tng <ackerleytng@google.com> Reviewed-by: Michael Roth <michael.roth@amd.com> Link: https://patch.msgid.link/20260709204948.1988414-11-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Add automatic panel recognition support for Waveshare DSI displays,targeting panels such as the 10.1inch DSI LCD (E) that identify themselves at runtime via I2C control registers.
Driver changes (drivers/gpu/drm/panel/panel-waveshare-dsi.c)
ws_panel_i2c_read()helper andws_panel_auto_detect()function which read screen type, rotation and refresh rate from registers 0xd0/0xd1/0xd3.waveshare,automatic-recognition-panelcompatible entry.Overlay changes (vc4-kms-dsi-waveshare-panel)
auto_recoverlay parameter selecting the automatic recognition panel, documented in the overlays README.