On Fri, Aug 04, 2023 at 11:45:59AM +0300, Jani Nikula wrote:
> The current display probe is unable to differentiate between IVB Q and
> IVB D GT2 server, as they both have the same device id, but different
> subvendor and subdevice. This leads to the latter being misidentified as
> the former, and should just end up not having a display. However, the no
> display case returns a NULL as the display device info, and promptly
> oopses.
>
> As the IVB Q case is rare, and we're anyway moving towards GMD ID,
> handle the identification requiring subvendor and subdevice as a special
> case first, instead of unnecessarily growing the intel_display_ids[]
> array with subvendor and subdevice.
>
> [ 5.425298] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [ 5.426059] #PF: supervisor read access in kernel mode
> [ 5.426810] #PF: error_code(0x0000) - not-present page
> [ 5.427570] PGD 0 P4D 0
> [ 5.428285] Oops: 0000 [#1] PREEMPT SMP PTI
> [ 5.429035] CPU: 0 PID: 137 Comm: (udev-worker) Not tainted 6.4.0-1-amd64 #1 Debian 6.4.4-1
> [ 5.429759] Hardware name: HP HP Z220 SFF Workstation/HP Z220 SFF Workstation, BIOS 4.19-218-gb184e6e0a1 02/02/2023
> [ 5.430485] RIP: 0010:intel_device_info_driver_create+0xf1/0x120 [i915]
> [ 5.431338] Code: 48 8b 97 80 1b 00 00 89 8f c0 1b 00 00 48 89 b7 b0 1b 00 00 48 89 97 b8 1b 00 00 0f b7 fd e8 76 e8 14 00 48 89 83 50 1b 00 00 <48> 8b 08 48 89 8b c4 1b 00 00 48 8b 48 08 48 89 8b cc 1b 00 00 8b
> [ 5.432920] RSP: 0018:ffffb8254044fb98 EFLAGS: 00010206
> [ 5.433707] RAX: 0000000000000000 RBX: ffff923076e80000 RCX: 0000000000000000
> [ 5.434494] RDX: 0000000000000260 RSI: 0000000100001000 RDI: 000000000000016a
> [ 5.435277] RBP: 000000000000016a R08: ffffb8254044fb00 R09: 0000000000000000
> [ 5.436055] R10: ffff922d02761de8 R11: 00657361656c6572 R12: ffffffffc0e5d140
> [ 5.436867] R13: ffff922d00b720d0 R14: 0000000076e80000 R15: ffff923078c0cae8
> [ 5.437646] FS: 00007febd19a18c0(0000) GS:ffff92307c000000(0000) knlGS:0000000000000000
> [ 5.438434] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 5.439218] CR2: 0000000000000000 CR3: 000000010256e002 CR4: 00000000001706f0
> [ 5.440009] Call Trace:
> [ 5.440824] <TASK>
> [ 5.441611] ? __die+0x23/0x70
> [ 5.442394] ? page_fault_oops+0x17d/0x4c0
> [ 5.443173] ? exc_page_fault+0x7f/0x180
> [ 5.443949] ? asm_exc_page_fault+0x26/0x30
> [ 5.444756] ? intel_device_info_driver_create+0xf1/0x120 [i915]
> [ 5.445652] ? intel_device_info_driver_create+0xea/0x120 [i915]
> [ 5.446545] i915_driver_probe+0x7f/0xb60 [i915]
> [ 5.447431] ? drm_privacy_screen_get+0x15c/0x1a0 [drm]
> [ 5.448240] local_pci_probe+0x45/0xa0
> [ 5.449013] pci_device_probe+0xc7/0x240
> [ 5.449748] really_probe+0x19e/0x3e0
> [ 5.450464] ? __pfx___driver_attach+0x10/0x10
> [ 5.451172] __driver_probe_device+0x78/0x160
> [ 5.451870] driver_probe_device+0x1f/0x90
> [ 5.452601] __driver_attach+0xd2/0x1c0
> [ 5.453293] bus_for_each_dev+0x88/0xd0
> [ 5.453989] bus_add_driver+0x116/0x220
> [ 5.454672] driver_register+0x59/0x100
> [ 5.455336] i915_init+0x25/0xc0 [i915]
> [ 5.456104] ? __pfx_i915_init+0x10/0x10 [i915]
> [ 5.456882] do_one_initcall+0x5d/0x240
> [ 5.457511] do_init_module+0x60/0x250
> [ 5.458126] __do_sys_finit_module+0xac/0x120
> [ 5.458721] do_syscall_64+0x60/0xc0
> [ 5.459314] ? syscall_exit_to_user_mode+0x1b/0x40
> [ 5.459897] ? do_syscall_64+0x6c/0xc0
> [ 5.460510] entry_SYSCALL_64_after_hwframe+0x72/0xdc
> [ 5.461082] RIP: 0033:0x7febd20b0eb9
> [ 5.461648] Code: 08 89 e8 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 2f 1f 0d 00 f7 d8 64 89 01 48
> [ 5.462905] RSP: 002b:00007fffabb1ba78 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
> [ 5.463554] RAX: ffffffffffffffda RBX: 0000561e6304f410 RCX: 00007febd20b0eb9
> [ 5.464201] RDX: 0000000000000000 RSI: 00007febd2244f0d RDI: 0000000000000015
> [ 5.464869] RBP: 00007febd2244f0d R08: 0000000000000000 R09: 000000000000000a
> [ 5.465512] R10: 0000000000000015 R11: 0000000000000246 R12: 0000000000020000
> [ 5.466124] R13: 0000000000000000 R14: 0000561e63032b60 R15: 000000000000000a
> [ 5.466700] </TASK>
> [ 5.467271] Modules linked in: i915(+) drm_buddy video crc32_pclmul sr_mod hid_generic wmi crc32c_intel i2c_algo_bit sd_mod cdrom drm_display_helper cec usbhid rc_core ghash_clmulni_intel hid sha512_ssse3 ttm sha512_generic xhci_pci ehci_pci xhci_hcd ehci_hcd nvme ahci drm_kms_helper nvme_core libahci t10_pi libata psmouse aesni_intel scsi_mod crypto_simd i2c_i801 scsi_common crc64_rocksoft_generic cryptd i2c_smbus drm lpc_ich crc64_rocksoft crc_t10dif e1000e usbcore crct10dif_generic usb_common crct10dif_pclmul crc64 crct10dif_common button
> [ 5.469750] CR2: 0000000000000000
> [ 5.470364] ---[ end trace 0000000000000000 ]---
> [ 5.470971] RIP: 0010:intel_device_info_driver_create+0xf1/0x120 [i915]
> [ 5.471699] Code: 48 8b 97 80 1b 00 00 89 8f c0 1b 00 00 48 89 b7 b0 1b 00 00 48 89 97 b8 1b 00 00 0f b7 fd e8 76 e8 14 00 48 89 83 50 1b 00 00 <48> 8b 08 48 89 8b c4 1b 00 00 48 8b 48 08 48 89 8b cc 1b 00 00 8b
> [ 5.473034] RSP: 0018:ffffb8254044fb98 EFLAGS: 00010206
> [ 5.473698] RAX: 0000000000000000 RBX: ffff923076e80000 RCX: 0000000000000000
> [ 5.474371] RDX: 0000000000000260 RSI: 0000000100001000 RDI: 000000000000016a
> [ 5.475045] RBP: 000000000000016a R08: ffffb8254044fb00 R09: 0000000000000000
> [ 5.475725] R10: ffff922d02761de8 R11: 00657361656c6572 R12: ffffffffc0e5d140
> [ 5.476405] R13: ffff922d00b720d0 R14: 0000000076e80000 R15: ffff923078c0cae8
> [ 5.477124] FS: 00007febd19a18c0(0000) GS:ffff92307c000000(0000) knlGS:0000000000000000
> [ 5.477811] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 5.478499] CR2: 0000000000000000 CR3: 000000010256e002 CR4: 00000000001706f0
>
> Fixes: 69d439818fe5 ("drm/i915/display: Make display responsible for probing its own IP")
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8991
> Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
> Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Reviewed-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
> ---
> .../drm/i915/display/intel_display_device.c | 24 ++++++++++++++++---
> 1 file changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
> index 8286e79522d1..3d6a262e037f 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -724,10 +724,24 @@ static const struct intel_display_device_info xe_lpdp_display = {
> BIT(PORT_TC1) | BIT(PORT_TC2) | BIT(PORT_TC3) | BIT(PORT_TC4),
> };
>
> +/*
> + * Separate detection for no display cases to keep the display id array simple.
> + *
> + * IVB Q requires subvendor and subdevice matching to differentiate from IVB D
> + * GT2 server.
> + */
> +static bool has_no_display(struct pci_dev *pdev)
> +{
> + static const struct pci_device_id ids[] = {
> + INTEL_IVB_Q_IDS(0),
> + {}
> + };
> +
> + return pci_match_id(ids, pdev);
> +}
> +
> #undef INTEL_VGA_DEVICE
> -#undef INTEL_QUANTA_VGA_DEVICE
> #define INTEL_VGA_DEVICE(id, info) { id, info }
> -#define INTEL_QUANTA_VGA_DEVICE(info) { 0x16a, info }
>
> static const struct {
> u32 devid;
> @@ -752,7 +766,6 @@ static const struct {
> INTEL_IRONLAKE_M_IDS(&ilk_m_display),
> INTEL_SNB_D_IDS(&snb_display),
> INTEL_SNB_M_IDS(&snb_display),
> - INTEL_IVB_Q_IDS(NULL), /* must be first IVB in list */
> INTEL_IVB_M_IDS(&ivb_display),
> INTEL_IVB_D_IDS(&ivb_display),
> INTEL_HSW_IDS(&hsw_display),
> @@ -837,6 +850,11 @@ intel_display_device_probe(struct drm_i915_private *i915, bool has_gmdid,
> if (has_gmdid)
> return probe_gmdid_display(i915, gmdid_ver, gmdid_rel, gmdid_step);
>
> + if (has_no_display(pdev)) {
> + drm_dbg_kms(&i915->drm, "Device doesn't have display\n");
> + return &no_display;
> + }
> +
> for (i = 0; i < ARRAY_SIZE(intel_display_ids); i++) {
> if (intel_display_ids[i].devid == pdev->device)
> return intel_display_ids[i].info;
> --
> 2.39.2
>
--
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation
