Re: [PATCH v2 6/8] media: platform: amd: isp4 video node and buffers handling added

Sultan Alsawaf
2025-07-31T00:34:27Z

On Tue, Jul 29, 2025 at 03:43:14PM +0800, Du, Bin wrote:
> Hi Sultan, really appreciate your time and effort
>
> On 7/28/2025 3:04 PM, Sultan Alsawaf wrote:
> > I found more refcounting issues in addition to the ones from my other emails
> > while trying to make my webcam work:
> >
> > On Wed, Jun 18, 2025 at 05:19:57PM +0800, Bin Du wrote:
> > > +static int isp4vid_vb2_mmap(void *buf_priv, struct vm_area_struct *vma)
> > > +{
> > > + struct isp4vid_vb2_buf *buf = buf_priv;
> > > + int ret;
> > > +
> > > + if (!buf) {
> > > + pr_err("fail no memory to map\n");
> > > + return -EINVAL;
> > > + }
> > > +
> > > + ret = remap_vmalloc_range(vma, buf->vaddr, 0);
> > > + if (ret) {
> > > + dev_err(buf->dev, "fail remap vmalloc mem, %d\n", ret);
> > > + return ret;
> > > + }
> > > +
> > > + /*
> > > + * Make sure that vm_areas for 2 buffers won't be merged together
> > > + */
> > > + vm_flags_set(vma, VM_DONTEXPAND);
> > > +
> > > + dev_dbg(buf->dev, "mmap isp user bo 0x%llx size %ld refcount %d\n",
> > > + buf->gpu_addr, buf->size, buf->refcount.refs.counter);
> >
> > Use refcount_read() instead of reading the refcount's atomic_t counter directly.
> > This is done in 3 other places; change those to refcount_read() as well.
> >
> > This didn't cause any functional problems, but it should still be fixed.
> >
> > > +
> > > + return 0;
> > > +}
> >
> Sure, will fix it
>
> > [snip]
> >
> > > +static void isp4vid_vb2_detach_dmabuf(void *mem_priv)
> > > +{
> > > + struct isp4vid_vb2_buf *buf = mem_priv;
> > > +
> > > + if (!buf) {
> > > + pr_err("fail invalid buf handle\n");
> > > + return;
> > > + }
> > > +
> > > + struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr);
> > > +
> > > + dev_dbg(buf->dev, "detach dmabuf of isp user bo 0x%llx size %ld",
> > > + buf->gpu_addr, buf->size);
> > > +
> > > + if (buf->vaddr)
> > > + dma_buf_vunmap_unlocked(buf->dbuf, &map);
> > > +
> > > + // put dmabuf for exported ones
> > > + dma_buf_put(buf->dbuf);
> > > +
> > > + kfree(buf);
> > > +}
> >
> > As mentioned in the other email, the dma_buf_put() here needs to be removed. But
> > that's not all: the dma_buf_vunmap_unlocked() needs to be removed too because
> > vb2 will always unmap the buffer before detaching it. As a result, having the
> > dma_buf_vunmap_unlocked() call here results in a use-after-free when vb2 calls
> > the unmap_dmabuf memop.
> >
> > Change this function to the following:
> >
> > static void isp4vid_vb2_detach_dmabuf(void *mem_priv)
> > {
> > struct isp4vid_vb2_buf *buf = mem_priv;
> >
> > kfree(buf);
> > }
> >
> Will have a try
>
> > > +static void isp4vid_qops_buffer_cleanup(struct vb2_buffer *vb)
> > > +{
> > > + struct isp4vid_dev *isp_vdev = vb2_get_drv_priv(vb->vb2_queue);
> > > + struct isp4vid_vb2_buf *buf = vb->planes[0].mem_priv;
> > > +
> > > + dev_dbg(isp_vdev->dev, "%s|index=%u vb->memory %u",
> > > + isp_vdev->vdev.name, vb->index, vb->memory);
> > > +
> > > + if (!buf) {
> > > + dev_err(isp_vdev->dev, "Invalid buf handle");
> > > + return;
> > > + }
> > > +
> > > + // release implicit dmabuf reference here for vb2 buffer
> > > + // of type MMAP and is exported
> > > + if (vb->memory == VB2_MEMORY_MMAP && buf->is_expbuf) {
> > > + dma_buf_put(buf->dbuf);
> > > + dev_dbg(isp_vdev->dev,
> > > + "put dmabuf for vb->memory %d expbuf %d",
> > > + vb->memory,
> > > + buf->is_expbuf);
> > > + }
> > > +}
> > > +
> >
> > Remove the isp4vid_qops_buffer_cleanup() function. It causes a use-after-free by
> > doing an extra dma_buf_put(). This function isn't needed now that the refcount
> > issues are solved.
> >
> Will have a try
>
> > [snip]
> >
> > > +static const struct vb2_ops isp4vid_qops = {
> > > + .queue_setup = isp4vid_qops_queue_setup,
> > > + .buf_cleanup = isp4vid_qops_buffer_cleanup,
> >
> > Remove the .buf_cleanup hook too.
> >
> Will have a try
>
> > > + .buf_queue = isp4vid_qops_buffer_queue,
> > > + .start_streaming = isp4vid_qops_start_streaming,
> > > + .stop_streaming = isp4vid_qops_stop_streaming,
> > > + .wait_prepare = vb2_ops_wait_prepare,
> > > + .wait_finish = vb2_ops_wait_finish,
> > > +};
> >
> > [snip]
> >
> > Along with the changes from my other emails, I believe this finally fixes all of
> > the refcounting issues. No more UaF or leaks here. :-)
> >
> > Sultan
> Tried changes in this and other two mails together, found the kernel will
> crash when re-open cheese App (means open cheese, close it and then open it
> again), the crash stack dump is shown below
>
> [ 38.008686] amdgpu 0000:c3:00.0: amdgpu: power on isp suc
> [ 38.032693] amdgpu 0000:c3:00.0: amdgpu: set xclk 788 suc, reg_val 800
> [ 38.060866] amdgpu 0000:c3:00.0: amdgpu: set iclk 788 suc, reg_val 792
> [ 38.060877] amdgpu 0000:c3:00.0: amdgpu: set xclk 788 iclk 788 to
> performance state 1 suc
> [ 38.425284] amdgpu 0000:c3:00.0: amdgpu: isp set performance do none to
> state 0
> [ 38.448631] amdgpu 0000:c3:00.0: amdgpu: power off isp suc
> [ 38.508368] amdgpu 0000:c3:00.0: amdgpu: power on isp suc
> [ 38.538525] amdgpu 0000:c3:00.0: amdgpu: set xclk 788 suc, reg_val 800
> [ 38.568839] amdgpu 0000:c3:00.0: amdgpu: set iclk 788 suc, reg_val 792
> [ 38.568851] amdgpu 0000:c3:00.0: amdgpu: set xclk 788 iclk 788 to
> performance state 1 suc
> [ 38.997779] amdgpu 0000:c3:00.0: amdgpu: isp set performance do none to
> state 0
> [ 39.029297] amdgpu 0000:c3:00.0: amdgpu: power off isp suc
> [ 39.084010] BUG: kernel NULL pointer dereference, address:
> 0000000000000008
> [ 39.084024] #PF: supervisor read access in kernel mode
> [ 39.084028] #PF: error_code(0x0000) - not-present page
> [ 39.084031] PGD 0 P4D 0
> [ 39.084037] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
> [ 39.084042] CPU: 3 UID: 1000 PID: 3119 Comm: viewfinderbin-q Not tainted
> 6.14.0-rc2+ #944
> [ 39.084046] Hardware name: HP HP ZBook Ultra G1a 14 inch Mobile
> Workstation PC/8D01, BIOS X89 Ver. 01.03.00 04/25/2025
> [ 39.084049] RIP: 0010:validate_page_before_insert+0x5/0xc0
> [ 39.084060] Code: 31 c9 31 ff 45 31 c0 c3 cc cc cc cc 66 0f 1f 84 00 00
> 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 <48>
> 8b 46 08 a8 01 75 7a 66 90 48 89 f0 8b 50 34 85 d2 0f 84 8c 00
> [ 39.084064] RSP: 0018:ffffb95e05e7b6a0 EFLAGS: 00010202
> [ 39.084067] RAX: 0000000000000000 RBX: 8000000000000025 RCX:
> 0000000000000000
> [ 39.084069] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
> ffff9efa10e400b8
> [ 39.084071] RBP: ffffb95e05e7b6e0 R08: 0000000000000000 R09:
> 0000000000000000
> [ 39.084072] R10: 0000000000000000 R11: 0000000000000000 R12:
> ffff9efa10e400b8
> [ 39.084074] R13: ffffb95e0e055000 R14: 00007fa3d6119000 R15:
> 0000000000000000
> [ 39.084076] FS: 00007fa3f4bf96c0(0000) GS:ffff9f050d780000(0000)
> knlGS:0000000000000000
> [ 39.084078] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 39.084080] CR2: 0000000000000008 CR3: 0000000137bba000 CR4:
> 0000000000750ef0
> [ 39.084083] PKRU: 55555554
> [ 39.084084] Call Trace:
> [ 39.084087] <TASK>
> [ 39.084093] ? show_regs+0x71/0x90
> [ 39.084099] ? __die+0x25/0x80
> [ 39.084102] ? page_fault_oops+0x15c/0x570
> [ 39.084108] ? do_user_addr_fault+0x4a9/0x810
> [ 39.084111] ? __mod_memcg_lruvec_state+0xde/0x280
> [ 39.084117] ? exc_page_fault+0x83/0x1d0
> [ 39.084123] ? asm_exc_page_fault+0x27/0x30
> [ 39.084131] ? validate_page_before_insert+0x5/0xc0
> [ 39.084134] ? vm_insert_page+0xd4/0x1a0
> [ 39.084139] remap_vmalloc_range_partial+0xe3/0x160
> [ 39.084145] remap_vmalloc_range+0x21/0x40
> [ 39.084153] isp4vid_vb2_mmap+0x2d/0x130 [amd_capture]
> [ 39.084164] isp4vid_vb2_dmabuf_ops_mmap+0x12/0x20 [amd_capture]
> [ 39.084168] dma_buf_mmap_internal+0x41/0x70
> [ 39.084173] __mmap_region+0x62f/0xbc0
> [ 39.084179] mmap_region+0x67/0xe0
> [ 39.084181] do_mmap+0x52b/0x650
> [ 39.084187] vm_mmap_pgoff+0xf4/0x1c0
> [ 39.084194] ksys_mmap_pgoff+0x182/0x250
> [ 39.084198] __x64_sys_mmap+0x33/0x70
> [ 39.084202] x64_sys_call+0x2541/0x26f0
> [ 39.084206] do_syscall_64+0x70/0x130
> [ 39.084212] ? __rseq_handle_notify_resume+0xa4/0x520
> [ 39.084216] ? do_futex+0x17f/0x220
> [ 39.084220] ? restore_fpregs_from_fpstate+0x3d/0xd0
> [ 39.084225] ? switch_fpu_return+0x50/0xe0
> [ 39.084229] ? syscall_exit_to_user_mode+0x18c/0x1c0
> [ 39.084234] ? do_syscall_64+0x7c/0x130
> [ 39.084237] ? __pfx_futex_wake_mark+0x10/0x10
> [ 39.084241] ? hrtimer_cancel+0x15/0x50
> [ 39.084246] ? futex_wait+0x7c/0x120
> [ 39.084249] ? __pfx_hrtimer_wakeup+0x10/0x10
> [ 39.084254] ? __rseq_handle_notify_resume+0xa4/0x520
> [ 39.084256] ? do_futex+0x17f/0x220
> [ 39.084258] ? restore_fpregs_from_fpstate+0x3d/0xd0
> [ 39.084261] ? switch_fpu_return+0x50/0xe0
> [ 39.084264] ? syscall_exit_to_user_mode+0x18c/0x1c0
> [ 39.084268] ? do_syscall_64+0x7c/0x130
> [ 39.084272] ? __count_memcg_events+0xcd/0x190
> [ 39.084276] ? count_memcg_events.constprop.0+0x2a/0x50
> [ 39.084279] ? handle_mm_fault+0x1ef/0x2d0
> [ 39.084284] ? do_user_addr_fault+0x58d/0x810
> [ 39.084286] ? irqentry_exit_to_user_mode+0x33/0x180
> [ 39.084291] ? irqentry_exit+0x43/0x50
> [ 39.084294] ? exc_page_fault+0x94/0x1d0
> [ 39.084298] entry_SYSCALL_64_after_hwframe+0x76/0x7e
> [ 39.084302] RIP: 0033:0x7fa463b2531c
> [ 39.084305] Code: 1e fa 41 f7 c1 ff 0f 00 00 75 33 55 48 89 e5 41 54 41
> 89 cc 53 48 89 fb 48 85 ff 74 41 45 89 e2 48 89 df b8 09 00 00 00 0f 05 <48>
> 3d 00 f0 ff ff 77 7c 5b 41 5c 5d c3 0f 1f 80 00 00 00 00 48 8b
> [ 39.084308] RSP: 002b:00007fa3f4bf79e0 EFLAGS: 00000246 ORIG_RAX:
> 0000000000000009
> [ 39.084311] RAX: ffffffffffffffda RBX: 0000000000000000 RCX:
> 00007fa463b2531c
> [ 39.084312] RDX: 0000000000000001 RSI: 00000000007782c0 RDI:
> 0000000000000000
> [ 39.084314] RBP: 00007fa3f4bf79f0 R08: 0000000000000047 R09:
> 0000000000000000
> [ 39.084315] R10: 0000000000000001 R11: 0000000000000246 R12:
> 0000000000000001
> [ 39.084317] R13: 0000000000000000 R14: 00007fa3f8019b48 R15:
> 00007fa3f4bf7b60
> [ 39.084320] </TASK>
> [ 39.084321] Modules linked in: snd_seq_dummy snd_hrtimer hid_sensor_prox
> hid_sensor_gyro_3d hid_sensor_trigger industrialio_triggered_buffer
> kfifo_buf hid_sensor_iio_common industrialio hid_sensor_hub rfcomm cmac
> algif_hash algif_skcipher af_alg hid_logitech_hidpp ov05c10 v4l2_cci
> amd_capture v4l2_fwnode videobuf2_memops videobuf2_v4l2 videobuf2_common
> v4l2_async videodev pinctrl_amdisp i2c_designware_amdisp qrtr bnep btusb
> btrtl btintel btbcm btmtk bluetooth hid_logitech_dj intel_rapl_msr amd_atl
> intel_rapl_common binfmt_misc nls_iso8859_1 snd_acp_legacy_mach snd_acp_mach
> snd_soc_nau8821 snd_acp3x_rn amdgpu edac_mce_amd snd_ctl_led
> snd_hda_codec_realtek snd_acp70 snd_hda_codec_generic snd_acp_i2s
> snd_acp_pdm snd_hda_scodec_component snd_soc_dmic snd_acp_pcm
> snd_sof_amd_rembrandt snd_sof_amd_renoir snd_sof_amd_acp snd_sof_pci
> snd_sof_xtensa_dsp snd_hda_codec_hdmi snd_sof snd_sof_utils snd_pci_ps
> snd_soc_acpi_amd_match snd_amd_sdw_acpi soundwire_amd
> soundwire_generic_allocation soundwire_bus snd_hda_intel kvm_amd
> [ 39.084385] snd_soc_sdca snd_intel_dspcfg snd_intel_sdw_acpi
> snd_soc_core snd_hda_codec amdxcp kvm snd_compress
> drm_panel_backlight_quirks snd_hda_core snd_usb_audio gpu_sched ac97_bus
> polyval_clmulni snd_pcm_dmaengine polyval_generic ghash_clmulni_intel
> drm_buddy snd_usbmidi_lib snd_seq_midi snd_rpl_pci_acp6x sha256_ssse3
> snd_ump drm_ttm_helper snd_seq_midi_event snd_hwdep sha1_ssse3 ttm
> aesni_intel drm_exec snd_rawmidi drm_suballoc_helper snd_acp_pci mc
> crypto_simd snd_acp_legacy_common drm_client_lib cryptd drm_display_helper
> snd_pci_acp6x snd_seq rapl hp_wmi cec wmi_bmof snd_pcm sparse_keymap
> snd_seq_device rc_core snd_timer snd_pci_acp5x drm_kms_helper
> snd_rn_pci_acp3x amd_pmf snd i2c_algo_bit snd_acp_config i2c_piix4
> snd_soc_acpi amdtee soundcore snd_pci_acp3x i2c_smbus ccp joydev tee
> input_leds serial_multi_instantiate amd_pmc platform_profile wireless_hotkey
> mac_hid serio_raw sch_fq_codel msr parport_pc ppdev lp parport efi_pstore
> nfnetlink dmi_sysfs ip_tables x_tables autofs4 r8152 mii usbhid
> hid_multitouch
> [ 39.084451] hid_generic nvme ucsi_acpi i2c_hid_acpi video typec_ucsi
> i2c_hid amd_sfh thunderbolt hid nvme_core typec wmi drm
> [ 39.084465] CR2: 0000000000000008
> [ 39.084468] ---[ end trace 0000000000000000 ]---
> [ 39.116114] amdgpu 0000:c3:00.0: amdgpu: power on isp suc
> [ 39.159519] amdgpu 0000:c3:00.0: amdgpu: set xclk 788 suc, reg_val 800
> [ 39.201325] amdgpu 0000:c3:00.0: amdgpu: set iclk 788 suc, reg_val 792
> [ 39.201334] amdgpu 0000:c3:00.0: amdgpu: set xclk 788 iclk 788 to
> performance state 1 suc
> [ 39.343894] RIP: 0010:validate_page_before_insert+0x5/0xc0
> [ 39.343907] Code: 31 c9 31 ff 45 31 c0 c3 cc cc cc cc 66 0f 1f 84 00 00
> 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 <48>
> 8b 46 08 a8 01 75 7a 66 90 48 89 f0 8b 50 34 85 d2 0f 84 8c 00
> [ 39.343909] RSP: 0018:ffffb95e05e7b6a0 EFLAGS: 00010202
> [ 39.343911] RAX: 0000000000000000 RBX: 8000000000000025 RCX:
> 0000000000000000
> [ 39.343913] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
> ffff9efa10e400b8
> [ 39.343913] RBP: ffffb95e05e7b6e0 R08: 0000000000000000 R09:
> 0000000000000000
> [ 39.343914] R10: 0000000000000000 R11: 0000000000000000 R12:
> ffff9efa10e400b8
> [ 39.343915] R13: ffffb95e0e055000 R14: 00007fa3d6119000 R15:
> 0000000000000000
> [ 39.343916] FS: 00007fa3f4bf96c0(0000) GS:ffff9f050d780000(0000)
> knlGS:0000000000000000
> [ 39.343917] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 39.343918] CR2: 0000000000000008 CR3: 0000000137bba000 CR4:
> 0000000000750ef0
> [ 39.343919] PKRU: 55555554
> [ 39.343920] note: viewfinderbin-q[3119] exited with irqs disabled
>
> This is the patch, it should have contained all your changes
>
> From b0a61b6b7500635928166516d5563e6de50300bb Mon Sep 17 00:00:00 2001
> From: Bin Du <Bin.Du@amd.com>
> Date: Mon, 28 Jul 2025 14:18:04 +0800
> Subject: [PATCH] add comment from community
>
> Change-Id: I06fff629c0dc691eaeaa9d9b81e6af27cbb6adb2
> ---
> drivers/media/platform/amd/isp4/isp4_video.c | 59 ++++++--------------
> 1 file changed, 17 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/media/platform/amd/isp4/isp4_video.c
> b/drivers/media/platform/amd/isp4/isp4_video.c
> index a1376498c246..b210a0b1e49b 100644
> --- a/drivers/media/platform/amd/isp4/isp4_video.c
> +++ b/drivers/media/platform/amd/isp4/isp4_video.c
> @@ -183,7 +183,7 @@ static int isp4vid_vb2_mmap(void *buf_priv, struct
> vm_area_struct *vma)
> vm_flags_set(vma, VM_DONTEXPAND);
>
> dev_dbg(buf->dev, "mmap isp user bo 0x%llx size %ld refcount %d\n",
> - buf->gpu_addr, buf->size, buf->refcount.refs.counter);
> + buf->gpu_addr, buf->size, refcount_read(&buf->refcount));
>
> return 0;
> }
> @@ -214,14 +214,9 @@ static void isp4vid_vb2_detach_dmabuf(void *mem_priv)
> return;
> }
>
> - struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr);
> -
> dev_dbg(buf->dev, "detach dmabuf of isp user bo 0x%llx size %ld",
> buf->gpu_addr, buf->size);
>
> - if (buf->vaddr)
> - dma_buf_vunmap_unlocked(buf->dbuf, &map);
> -
> kfree(buf);
> }
>
> @@ -470,21 +465,25 @@ static struct dma_buf *isp4vid_vb2_get_dmabuf(struct
> vb2_buffer *vb,
> unsigned long flags)
> {
> struct isp4vid_vb2_buf *buf = buf_priv;
> - struct dma_buf *dbuf;
> + struct dma_buf *dbuf = buf->dbuf;
> +
> + if (dbuf) {
> + dev_dbg(buf->dev, "dbuf already created, reuse %s dbuf\n",
> + buf->is_expbuf ? "exported" : "implicit");
> + get_dma_buf(dbuf);
>
> - if (buf->dbuf) {
> - dev_dbg(buf->dev, "dbuf already created, reuse implicit dbuf\n");
> - dbuf = buf->dbuf;
> } else {
> dbuf = isp4vid_get_dmabuf(vb, buf_priv, flags);
> + if (!dbuf)
> + return NULL;
> +
> dev_dbg(buf->dev, "created new dbuf\n");
> + buf->is_expbuf = true;
> + refcount_inc(&buf->refcount);
> }
>
> - buf->is_expbuf = true;
> - refcount_inc(&buf->refcount);
> -
> dev_dbg(buf->dev, "buf exported, refcount %d\n",
> - buf->refcount.refs.counter);
> + refcount_read(&buf->refcount));
>
> return dbuf;
> }
> @@ -579,8 +578,9 @@ static void isp4vid_vb2_put(void *buf_priv)
> {
> struct isp4vid_vb2_buf *buf = (struct isp4vid_vb2_buf *)buf_priv;
> unsigned int ref_cnt = refcount_read(&buf->refcount);
> + struct device *dev = buf->dev;
>
> - dev_dbg(buf->dev,
> + dev_dbg(dev,
> "release isp user bo 0x%llx size %ld refcount %u is_expbuf %d\n",
> buf->gpu_addr, buf->size,
> ref_cnt, buf->is_expbuf);
> @@ -598,7 +598,7 @@ static void isp4vid_vb2_put(void *buf_priv)
> /* the ref_cnt - 1 is just a predicted value as reference, can't
> * guarantee it's the actual value now
> */
> - dev_warn(buf->dev, "ignore buffer free, refcount %u > 0\n", ref_cnt - 1);
> + dev_warn(dev, "ignore buffer free, refcount %u > 0\n", ref_cnt - 1);
> }
> }
>
> @@ -642,7 +642,7 @@ static void *isp4vid_vb2_alloc(struct vb2_buffer *vb,
> struct device *dev,
> refcount_set(&buf->refcount, 1);
>
> dev_dbg(dev, "allocated isp user bo 0x%llx size %ld refcount %d\n",
> - buf->gpu_addr, buf->size, buf->refcount.refs.counter);
> + buf->gpu_addr, buf->size, refcount_read(&buf->refcount));
>
> return buf;
> err_free:
> @@ -1140,30 +1140,6 @@ static void isp4vid_qops_buffer_queue(struct
> vb2_buffer *vb)
> mutex_unlock(&isp_vdev->buf_list_lock);
> }
>
> -static void isp4vid_qops_buffer_cleanup(struct vb2_buffer *vb)
> -{
> - struct isp4vid_dev *isp_vdev = vb2_get_drv_priv(vb->vb2_queue);
> - struct isp4vid_vb2_buf *buf = vb->planes[0].mem_priv;
> -
> - dev_dbg(isp_vdev->dev, "%s|index=%u vb->memory %u",
> - isp_vdev->vdev.name, vb->index, vb->memory);
> -
> - if (!buf) {
> - dev_err(isp_vdev->dev, "Invalid buf handle");
> - return;
> - }
> -
> - // release implicit dmabuf reference here for vb2 buffer
> - // of type MMAP and is exported
> - if (vb->memory == VB2_MEMORY_MMAP && buf->is_expbuf) {
> - dma_buf_put(buf->dbuf);
> - dev_dbg(isp_vdev->dev,
> - "put dmabuf for vb->memory %d expbuf %d",
> - vb->memory,
> - buf->is_expbuf);
> - }
> -}
> -
> static int isp4vid_qops_start_streaming(struct vb2_queue *vq,
> unsigned int count)
> {
> @@ -1343,7 +1319,6 @@ static int isp4vid_fill_buffer_size(struct isp4vid_dev
> *isp_vdev)
>
> static const struct vb2_ops isp4vid_qops = {
> .queue_setup = isp4vid_qops_queue_setup,
> - .buf_cleanup = isp4vid_qops_buffer_cleanup,
> .buf_queue = isp4vid_qops_buffer_queue,
> .start_streaming = isp4vid_qops_start_streaming,
> .stop_streaming = isp4vid_qops_stop_streaming,
> --
> 2.34.1

The patch looks correct. I will get back to you on this after doing some testing
myself.

FYI, I can only test these changes with the old isp4 driver right now, since the
new isp4 driver doesn't work for me as mentioned in my other email. So far,
something does seem wrong after these changes I suggested because they break the
camera on the old isp4 driver too.

Sultan