• Yong Wu's avatar
    memory: mtk-smi: Degrade SMI init to module_init · 4f608d38
    Yong Wu authored
    The initialization of MediaTek power manager(SCPSYS) is
    builtin_platform_driver, and SMI must depend on power-domain.
    Thus, currently subsys_initcall for SMI is unnecessary, SMI will be
    always probe defered by power-domain. Degrade it to module_init.
    
    In addition, there are two small changes about the probe sequence:
    1) Delete this two lines.
        	if (!dev->pm_domain)
    		return -EPROBE_DEFER;
       This is not helpful. the platform driver framework guarantee this.
       The "dev_pm_domain_attach" in the "platform_drv_probe" will return
       EPROBE_DEFER if its powerdomain is not ready.
    
    2) Add the probe-defer for the smi-larb device should waiting for
       smi-common.
       In mt2712, there are 2 smi-commons, 10 smi-larbs. All will be
       probe-defered by the power-domain, there is seldom case that
       smi-larb probe done before smi-common. then it will hang like
       this:
    
       Unable to handle kernel NULL pointer dereference at virtual address
    00000000 pgd = ffffff800a4e0000
    [00000000] *pgd=00000000beffe003[   17.610026] , *pud=00000000beffe003
    ...
    [<ffffff800897fe04>] mtk_smi_enable+0x1c/0xd0
    [<ffffff800897fee8>] mtk_smi_larb_get+0x30/0x98
    [<ffffff80088edfa8>] mtk_mipicsi0_resume+0x38/0x1b8
    [<ffffff8008634f44>] pm_generic_runtime_resume+0x3c/0x58
    [<ffffff8008644ff8>] __genpd_runtime_resume+0x38/0x98
    [<ffffff8008647434>] genpd_runtime_resume+0x164/0x220
    [<ffffff80086372f8>] __rpm_callback+0x78/0xa0
    [<ffffff8008637358>] rpm_callback+0x38/0xa0
    [<ffffff8008638a4c>] rpm_resume+0x4a4/0x6f8
    [<ffffff8008638d04>] __pm_runtime_resume+0x64/0xa0
    [<ffffff80088ed05c>] mtk_mipicsi0_probe+0x40c/0xb70
    [<ffffff800862cdc0>] platform_drv_probe+0x58/0xc0
    [<ffffff800862a514>] driver_probe_device+0x284/0x438
    [<ffffff800862a8ac>] __device_attach_driver+0xb4/0x160
    [<ffffff8008627d58>] bus_for_each_drv+0x68/0xa8
    [<ffffff800862a0a4>] __device_attach+0xd4/0x168
    [<ffffff800862a9d4>] device_initial_probe+0x24/0x30
    [<ffffff80086291d8>] bus_probe_device+0xa0/0xa8
    [<ffffff8008629784>] deferred_probe_work_func+0x94/0xf0
    [<ffffff80080f03a8>] process_one_work+0x1d8/0x6e0
    Signed-off-by: 's avatarYong Wu <yong.wu@mediatek.com>
    Signed-off-by: 's avatarJoerg Roedel <jroedel@suse.de>
    4f608d38