[SRU][E/F/U][PATCH 0/2] drm/i915: Add new CNL PCH ID seen on a CML platform

[Timo Aaltonen]

On 13.11.2019 13.14, You-Sheng Yang wrote:
> From: You-Sheng Yang <vicamo at gmail.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1852386
> 
> [Impact]
> Some Comet Lake platforms got i915 call trace dump due to the lake of
> support to its PCH id:
> 
>   [    2.999233] ------------[ cut here ]------------
>   [    2.999238] eDP powered off while attempting aux channel
>   communication.
>   [    2.999338] WARNING: CPU: 2 PID: 296 at
>   drivers/gpu/drm/i915/display/intel_dp.c:1148
>   intel_dp_aux_xfer+0x767/0x900 [i915]
>   [    2.999341] Modules linked in: i915(+) i2c_algo_bit drm_kms_helper
>   syscopyarea sysfillrect sysimgblt fb_sys_fops drm r8169 ahci realtek
>   libahci wmi video
>   [    2.999350] CPU: 2 PID: 296 Comm: systemd-udevd Not tainted
>   5.3.0-997-generic #201910072204
>   [    2.999352] Hardware name: Dell Inc. OptiPlex 3280 AIO/, BIOS
>   99.00.08 10/01/2019
>   [    2.999391] RIP: 0010:intel_dp_aux_xfer+0x767/0x900 [i915]
>   [    2.999394] Code: e8 ee b5 ff ff 84 c0 0f 85 ec f9 ff ff 48 8b 7d 80
>   e8 5d b6 ff ff 84 c0 0f 85 db f9 ff ff 48 c7 c7 50 22 5d c0 e8 84 ea b5
>   d1 <0f> 0b 48 8b 7d 80 48 8d 75 90 4c 8d ab a8 07 00 00 e8 63 b4 ff ff
>   [    2.999398] RSP: 0018:ffffb7000040b5b8 EFLAGS: 00010286
>   [    2.999400] RAX: 0000000000000000 RBX: ffff9bfa9dc20000 RCX:
>   0000000000000396
>   [    2.999402] RDX: 0000000000000001 RSI: 0000000000000082 RDI:
>   0000000000000246
>   [    2.999404] RBP: ffffb7000040b698 R08: 0000000000000396 R09:
>   0000000000000019
>   [    2.999406] R10: 000000000000072e R11: ffffb7000040b420 R12:
>   0000000000000004
>   [    2.999408] R13: ffff9bfa9fbca120 R14: ffff9bfa9dc20000 R15:
>   ffff9bfa9dc207a8
>   [    2.999410] FS:  00007f0d8613a680(0000) GS:ffff9bfaaec80000(0000)
>   knlGS:0000000000000000
>   [    2.999412] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>   [    2.999414] CR2: 00007ffca955ae58 CR3: 000000041e67e002 CR4:
>   00000000003606e0
>   [    2.999416] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
>   0000000000000000
>   [    2.999418] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
>   0000000000000400
>   [    2.999420] Call Trace:
>   [    2.999425]  ? vprintk_default+0x29/0x50
>   [    2.999464]  intel_dp_aux_transfer+0x15e/0x220 [i915]
>   [    2.999472]  drm_dp_dpcd_access+0x72/0x110 [drm_kms_helper]
>   [    2.999478]  drm_dp_dpcd_read+0x33/0xc0 [drm_kms_helper]
>   [    2.999515]  intel_dp_read_dpcd+0x41/0x130 [i915]
>   [    2.999551]  intel_edp_init_connector+0x136/0x540 [i915]
>   [    2.999587]  intel_dp_init_connector+0x47f/0x870 [i915]
>   [    2.999623]  intel_ddi_init+0x425/0x590 [i915]
>   [    2.999660]  intel_setup_outputs+0x8e4/0xc60 [i915]
> 
> [Fix]
> Two patches to be backported to have correct support:
> * commit 37c92dc303dd "drm/i915: Add new CNL PCH ID seen on a CML
>   platform" from drm-tip tree.
> * patch "https://patchwork.freedesktop.org/patch/340416"

I think you should drop the first patch and modify the second to apply
directly. No need to add the regressing patch.


-- 
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