Re: [PATCH v5 4/4] tpm: tpm_tis_spi: Support cr50 devices

[Heiko Stuebner <heiko@sntech.de>]

Am Mittwoch, 28. August 2019, 10:21:50 CEST schrieb Stephen Boyd:
> Add TPM2.0 PTP FIFO compatible SPI interface for chips with Cr50
> firmware. The firmware running on the currently supported H1 Secure
> Microcontroller requires a special driver to handle its specifics:
> 
>  - need to ensure a certain delay between SPI transactions, or else
>    the chip may miss some part of the next transaction
>  - if there is no SPI activity for some time, it may go to sleep,
>    and needs to be waken up before sending further commands
>  - access to vendor-specific registers
> 
> Cr50 firmware has a requirement to wait for the TPM to wakeup before
> sending commands over the SPI bus. Otherwise, the firmware could be in
> deep sleep and not respond. The method to wait for the device to wakeup
> is slightly different than the usual flow control mechanism described in
> the TCG SPI spec. Add a completion to tpm_tis_spi_transfer() before we
> start a SPI transfer so we can keep track of the last time the TPM
> driver accessed the SPI bus to support the flow control mechanism.

While the previous version did run just fine on my mainline gru-scarlet,
this v5 very persistently runs into a panic on every boot:

[    6.625500] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[    6.632983] tpm_tis_spi spi1.0: Timeout waiting for TPM ready IRQ
[    6.637415] Mem abort info:
[    6.637417]   ESR = 0x96000004
[    6.637419]   Exception class = DABT (current EL), IL = 32 bits
[    6.637423]   SET = 0, FnV = 0
[    6.644235] tpm_tis_spi spi1.0: TPM ready IRQ confirmed on attempt 1
[    6.647350]   EA = 0, S1PTW = 0
[    6.647352] Data abort info:
[    6.647353]   ISV = 0, ISS = 0x00000004
[    6.647354]   CM = 0, WnR = 0
[    6.647357] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000eacc4000
[    6.647361] [0000000000000000] pgd=0000000000000000
[    6.694812] Internal error: Oops: 96000004 [#1] SMP
[    6.700258] Modules linked in: tpm_tis_spi_mod(+) dw_mipi_dsi industrialio_triggered_buffer panfrost(+) drm_kms_helper videobuf2_memops kfifo_buf tpm_tis_core ov2685 ov5695 cros_ec_sensors_core videobuf2_v4l2 gpu_sched tpm videobuf2_common v4l2_common v4l2_fwnode crct10dif_ce drm videodev phy_rockchip_pcie phy_rockchip_dphy dw_wdt rng_core cros_ec_dev rockchip_thermal i2c_hid elants_i2c mc drm_panel_orientation_quirks pwm_bl ipv6
[    6.742857] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc6-02924-gef15fcdb727f-dirty #1308
[    6.752580] Hardware name: Google Scarlet (DT)
[    6.757542] pstate: a0000085 (NzCv daIf -PAN -UAO)
[    6.762901] pc : __wake_up_common+0x58/0x170
[    6.767670] lr : __wake_up_locked+0x18/0x20
[    6.772340] sp : ffff000010003d40
[    6.776038] x29: ffff000010003d40 x28: 0000000000000060 
[    6.781972] x27: 0000000000000000 x26: ffff000010e4fcef 
[    6.787905] x25: 0000000000000001 x24: 0000000000000000 
[    6.793838] x23: 0000000000000000 x22: 0000000000000000 
[    6.799772] x21: 0000000000000003 x20: ffff8000f0431308 
[    6.804944] dwmmc_rockchip fe320000.dwmmc: Unexpected data interrupt latency
[    6.805707] x19: ffff8000f04312f8 x18: 0000000000000000 
[    6.819504] x17: 0000000000000000 x16: 0000000000000000 
[    6.825437] x15: 0000000000000000 x14: 0000000000000000 
[    6.831370] x13: 0000000000000000 x12: ffff000010dc9688 
[    6.837304] x11: 071c71c71c71c71c x10: 0000000000000040 
[    6.843237] x9 : ffff000010de15d8 x8 : ffff000010de15d0 
[    6.849171] x7 : ffffffffffffffe8 x6 : 0000000000000000 
[    6.855104] x5 : 0000000000000000 x4 : 0000000000000000 
[    6.856947] tpm_tis_spi spi1.0: SPI transfer timed out
[    6.861037] x3 : 0000000000000000 x2 : 0000000000000001 
[    6.861040] x1 : 0000000000000003 x0 : 0000000000000000 
[    6.861045] Call trace:
[    6.866794] spi_master spi1: failed to transfer one message from queue
[    6.872724]  __wake_up_common+0x58/0x170
[    6.872727]  __wake_up_locked+0x18/0x20
[    6.872732]  complete+0x74/0xa8
[    6.900836]  cr50_spi_irq_handler+0x18/0x28 [tpm_tis_spi_mod]
[    6.907258]  __handle_irq_event_percpu+0x6c/0x170
[    6.912512]  handle_irq_event_percpu+0x34/0x88
[    6.917474]  handle_irq_event+0x40/0x98
[    6.921756]  handle_edge_irq+0xcc/0x208
[    6.926039]  generic_handle_irq+0x24/0x38
[    6.930516]  rockchip_irq_demux+0x9c/0x1f0
[    6.935091]  generic_handle_irq+0x24/0x38
[    6.939567]  __handle_domain_irq+0x60/0xb8
[    6.944140]  gic_handle_irq+0xa8/0x148
[    6.948326]  el1_irq+0xb8/0x140
[    6.951834]  cpuidle_enter_state+0x84/0x360
[    6.956506]  cpuidle_enter+0x34/0x48
[    6.960496]  call_cpuidle+0x1c/0x40
[    6.964388]  do_idle+0x270/0x2a0
[    6.967991]  cpu_startup_entry+0x20/0x28
[    6.972371]  rest_init+0xb4/0xc0
[    6.975976]  arch_call_rest_init+0xc/0x14
[    6.980452]  start_kernel+0x444/0x470
[    6.984543] Code: aa0503f8 f9002bfb aa0403f7 5280001b (f9400cf3) 
[    6.991357] ---[ end trace 0371d5a99c07b7ba ]---
[    6.996513] Kernel panic - not syncing: Fatal exception in interrupt
[    7.003613] SMP: stopping secondary CPUs
[    7.007994] Kernel Offset: disabled
[    7.011887] CPU features: 0x0002,2100600c
[    7.016362] Memory Limit: none
[    7.019763] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---


Heiko