[PATCH v2 2/2] drm/msm/dp: rewrite dss_module_power to use bulk clock functions

[Dmitry Baryshkov]

HI,

On Wed, 29 Dec 2021 at 07:12, Bjorn Andersson
<bjorn.andersson at linaro.org> wrote:
>
> On Thu 25 Nov 20:35 CST 2021, Dmitry Baryshkov wrote:
>
> > In order to simplify DP code, drop hand-coded loops over clock arrays,
> > replacing them with clk_bulk_* functions.
> >
>
> I've yet to debug this, but applying the two patches and attaching an
> HDMI cable to my USB dongle results in the follwing splat on the 8350
> HDK.

Intersesting. The only major difference between original code and the
patches code in this function is the removal of `if (clk_arry[i].clk)`
condition in that function. Could yyou please check whether clocks are
properly parsed at the time you receive the hpd event?

If  we can not debug this issue,  I'd then propose to merge first
patch and let somebody else rewrite dp_clk_util to use clk_bulk_data.

>
> [   39.658840] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
> [   39.667883] Mem abort info:
> [   39.670774]   ESR = 0x96000006
> [   39.673940]   EC = 0x25: DABT (current EL), IL = 32 bits
> [   39.679417]   SET = 0, FnV = 0
> [   39.682582]   EA = 0, S1PTW = 0
> [   39.685825]   FSC = 0x06: level 2 translation fault
> [   39.690851] Data abort info:
> [   39.693838]   ISV = 0, ISS = 0x00000006
> [   39.697797]   CM = 0, WnR = 0
> [   39.700864] user pgtable: 4k pages, 48-bit VAs, pgdp=000000010eb8d000
> [   39.707501] [0000000000000000] pgd=080000010f097003, p4d=080000010f097003, pud=080000010ba58003, pmd=0000000000000000
> [   39.718425] Internal error: Oops: 96000006 [#1] PREEMPT SMP
> [   39.724169] Modules linked in: pmic_glink_altmode qcom_pmic_glink_power cfg80211 rfkill 8021q garp mrp stp llc microchip lan78xx snd_soc_hdmi_codec pmic_glink pdr_interface rpmsg_char qrtr_smd qrtr fsa4480 qcom_q6v5_pas qcom_pil_info i2c_qcom_geni qcom_q6v5 msm qcom_sysmon qcom_stats gpu_sched crct10dif_ce drm_kms_helper qcom_common qcom_glink_smem gpucc_sm8350 phy_qcom_qmp mdt_loader typec ufs_qcom qmi_helpers qcom_rng socinfo qnoc_sm8350 rmtfs_mem fuse drm ipv6
> [   39.766330] CPU: 0 PID: 85 Comm: kworker/0:3 Not tainted 5.16.0-rc5-next-20211215-00046-g2f90133452d9 #280
> [   39.776256] Hardware name: Qualcomm Technologies, Inc. SM8350 HDK (DT)
> [   39.782969] Workqueue: events pmic_glink_altmode_worker [pmic_glink_altmode]
> [   39.790235] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [   39.797393] pc : __pi_strcmp+0x1c/0xf0
> [   39.801271] lr : dp_ctrl_set_clock_rate+0x8c/0xf0 [msm]
> [   39.806737] sp : ffff800008adbbc0
> [   39.810153] x29: ffff800008adbbc0 x28: 0000000000000000 x27: 0000000000000000
> [   39.817501] x26: ffffb60107f74270 x25: ffff297a49b33c80 x24: 00000000202fbf00
> [   39.824846] x23: 0000000000000001 x22: ffff297a4b400580 x21: 0000000000000020
> [   39.832188] x20: ffffb600e3d78068 x19: 0000000000000000 x18: ffffffffffffffff
> [   39.839541] x17: 6b6c63206e6f2030 x16: ffffb601063476c0 x15: 0720072007200720
> [   39.846893] x14: 0720072007200720 x13: ffffb60107c622c8 x12: 0000000000000765
> [   39.854229] x11: 0000000000000277 x10: 0101010101010101 x9 : ffffb60107c622c8
> [   39.861565] x8 : 00000000ffffefff x7 : 0000000000000000 x6 : ffffb60107cba2c8
> [   39.868902] x5 : 0000000000000000 x4 : ffff297cbe8619d8 x3 : 0000000000000000
> [   39.876240] x2 : 0000000000000000 x1 : ffffb600e3d78068 x0 : 0000000000000000
> [   39.883594] Call trace:
> [   39.886124]  __pi_strcmp+0x1c/0xf0
> [   39.889638]  dp_ctrl_enable_mainlink_clocks+0x98/0x110 [msm]
> [   39.895537]  dp_ctrl_on_link+0x98/0x3f0 [msm]
> [   39.900096]  dp_display_process_hpd_high+0xa8/0x100 [msm]
> [   39.905731]  dp_display_usbpd_attention_cb+0x164/0x1a4 [msm]
> [   39.911629]  dp_hpd_oob_event+0x74/0xa4 [msm]
> [   39.916195]  dp_display_oob_hotplug_event+0x1c/0x2c [msm]
> [   39.921831]  dp_oob_hotplug_event+0x18/0x24 [msm]
> [   39.926756]  drm_connector_oob_hotplug_event+0x40/0x60 [drm]
> [   39.932686]  pmic_glink_altmode_worker+0x7c/0x194 [pmic_glink_altmode]
> [   39.939398]  process_one_work+0x1d0/0x350
> [   39.943526]  worker_thread+0x13c/0x460
> [   39.947390]  kthread+0x17c/0x190
> [   39.950722]  ret_from_fork+0x10/0x20
> [   39.954416] Code: f24008ff 540003e1 f2400807 54000241 (f8408402)
> [   39.960684] ---[ end trace 0000000000000000 ]---
>
> Regards,
> Bjorn



-- 
With best wishes
Dmitry