Message-ID: <CAHCN7xLt6QqHodd=0HKXBxLjjn8ua5Re7NYW=sPeH+TmnXpkJQ@mail.gmail.com>
Date:   Mon, 19 Mar 2018 12:52:25 -0500
From:   Adam Ford <aford173@...il.com>
To:     Bartosz Golaszewski <bgolaszewski@...libre.com>
Cc:     David Lechner <david@...hnology.com>, linux-clk@...r.kernel.org,
        linux-devicetree <devicetree@...r.kernel.org>,
        arm-soc <linux-arm-kernel@...ts.infradead.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...eaurora.org>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Sekhar Nori <nsekhar@...com>,
        Kevin Hilman <khilman@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v8 00/42] ARM: davinci: convert to common clock framework​

On Mon, Mar 19, 2018 at 11:15 AM, Bartosz Golaszewski
<bgolaszewski@...libre.com> wrote:
> 2018-03-19 17:14 GMT+01:00 Bartosz Golaszewski <bgolaszewski@...libre.com>:
>> 2018-03-19 17:11 GMT+01:00 Adam Ford <aford173@...il.com>:
>>> On Mon, Mar 19, 2018 at 10:59 AM, David Lechner <david@...hnology.com> wrote:
>>>> On 03/19/2018 08:17 AM, Bartosz Golaszewski wrote:
>>>>>
>>>>> 2018-03-16 3:52 GMT+01:00 David Lechner <david@...hnology.com>:
>>>>>>
>>>>>> This series converts mach-davinci to use the common clock framework.
>>>>>>
>>>>>> The series works like this, the first 19 patches create new clock drivers
>>>>>> using the common clock framework. There are basically 3 groups of clocks
>>>>>> -
>>>>>> PLL, PSC and CFGCHIP (syscon). There are six different SoCs that each
>>>>>> have
>>>>>> unique init data, which is the reason for so many patches.
>>>>>>
>>>>>> Then, starting with "ARM: davinci: pass clock as parameter to
>>>>>> davinci_timer_init()", we get the mach code ready for the switch by
>>>>>> adding the
>>>>>> code needed for the new clock drivers and adding #ifndef
>>>>>> CONFIG_COMMON_CLK
>>>>>> around the legacy clocks so that we can switch easily between the old and
>>>>>> the
>>>>>> new.
>>>>>>
>>>>>> "ARM: davinci: switch to common clock framework" actually flips the
>>>>>> switch
>>>>>> to start using the new clock drivers. Then the next 8 patches remove all
>>>>>> of the old clock code.
>>>>>>
>>>>>> The final three patches add device tree clock support to the one SoC that
>>>>>> supports it.
>>>>>>
>>>>>> This series has been tested on LEGO MINDSTORMS EV3 (device tree) and TI
>>>>>> OMAP-L138 LCDK (both device tree and legacy board file).
>>>>>>


Does anyone have an LCD connected to the LCDC controller with device
tree?  I posted an RFC patch a while ago for the DA850-EVM, but I got
distracted and forgot about it, so I never working on getting the
patch ready for acceptance.

I am trying to test the LCD now, but I cannot get the screen to come
up, but in the process, it appears as if the clocking to the LCD isn't
quite right.  I know it used to work, but I am going to probe some
pins, but I am getting warning messages I have never received before.
The desired clock frequency is 9000000, but when I use the cpufreq in
ondemand mode, I get the following messages:

#  echo ondemand > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
# tilcdc 1e13000.display: tilcdc_crtc_irq(0x00000161): FIFO underflow
tilcdc 1e13000.display: effective pixel clock rate (50000000Hz) differs from the
 calculated rate (54000000Hz)
tilcdc 1e13000.display: effective pixel clock rate (50000000Hz) differs from the
 calculated rate (54000000Hz)
tilcdc 1e13000.display: tilcdc_crtc_irq(0x00000161): FIFO underflow
tilcdc 1e13000.display: tilcdc_crtc_irq(0x00000161): FIFO underflow
tilcdc 1e13000.display: effective pixel clock rate (50000000Hz) differs from the
 calculated rate (54000000Hz)
tilcdc 1e13000.display: effective pixel clock rate (50000000Hz) differs from the
 calculated rate (54000000Hz)
tilcdc 1e13000.display: tilcdc_crtc_irq(0x00000161): FIFO underflow
tilcdc 1e13000.display: tilcdc_crtc_irq(0x00000161): FIFO underflow
tilcdc 1e13000.display: effective pixel clock rate (50000000Hz) differs from the
 calculated rate (54000000Hz)
tilcdc 1e13000.display: effective pixel clock rate (50000000Hz) differs from the
 calculated rate (54000000Hz)
tilcdc 1e13000.display: tilcdc_crtc_irq(0x00000161): FIFO underflow

As ondemend is used and the processor scaling happens, the above
message appears on and off.

I do not know if it impacts the LCD image since I haven't been able to
get it working yet, but I'll troubleshoot it and when/if I can get the
LCD working, I'll turn on the ondemand again and see how it behaves.

adam


>>>>>
>>>>> Hi David,
>>>>>
>>>>> thanks, with the u-boot fix everything seems to work fine. I tested
>>>>> da850-lcdk and da850-evm boards in DT and board file modes.
>>>>>
>>>
>>> I tested MMC and Ethernet.  Both appear to be operating normally, but
>>> I have having USB issues.
>>>
>>> Should I be testing cpufreq?  I noticed that when changing the
>>> frequencies, the USB appears to stop recognizing connections and
>>> disconnections.
>>>
>>> I did some testing on the DA850-EVM with USB from your repo, and I'm
>>> getting some crashing on MUSB unplug that do not appear in the
>>> 4.16-RC6 from linux-stable:
>>>
>>>
>>> ------------[ cut here ]------------
>>> WARNING: CPU: 0 PID: 13 at drivers/dma/cppi41.c:694
>>> cppi41_stop_chan+0x1f4/0x378 [cppi41]
>>> Modules linked in: evbug evdev mousedev hid_generic usbhid hid
>>> usb_f_ss_lb g_zero libcomposite configfs ofpart cmdlinepart m25p80
>>> spi_nor cppi41 adv7343 tvp514x vpif_display vpif_capture
>>> videobuf2_dma_con
>>> tig videobuf2_memops videobuf2_v4l2 videobuf2_common v4l2_fwnode
>>> v4l2_common snd_soc_simple_card tilcdc spi_davinci
>>> snd_soc_simple_card_utils videodev pwm_tiecap spi_bitbang da8xx
>>> drm_kms_helper phy_gener
>>> ic syscopyarea ohci_da8xx musb_hdrc sysfillrect sysimgblt fb_sys_fops
>>> ohci_hcd udc_core drm usbcore drm_panel_orientation_quirks usb_common
>>> snd_soc_tlv320aic3x vpif snd_soc_davinci_mcasp snd_soc_edma snd_
>>> soc_core snd_pcm_dmaengine snd_pcm rtc_omap snd_timer snd soundcore
>>> phy_da8xx_usb davinci_nand nand nand_ecc mtd pwm_bl backlight
>>> cpufreq_dt ti_aemif
>>> CPU: 0 PID: 13 Comm: kworker/0:1 Not tainted 4.16.0-rc5-g291ba8b-dirty #3
>>> Hardware name: Generic DA850/OMAP-L138/AM18x
>>> Workqueue: usb_hub_wq hub_event [usbcore]
>>> Backtrace:
>>> [<c000df94>] (dump_backtrace) from [<c000e264>] (show_stack+0x18/0x1c)
>>>  r7:00000009 r6:00000000 r5:bf339ad0 r4:00000000
>>> [<c000e24c>] (show_stack) from [<c04864c0>] (dump_stack+0x20/0x28)
>>> [<c04864a0>] (dump_stack) from [<c001ac38>] (__warn+0xd4/0xfc)
>>> [<c001ab64>] (__warn) from [<c001ad7c>] (warn_slowpath_null+0x44/0x50)
>>>  r8:c6c43080 r7:c05f1008 r6:bf338744 r5:000002b6 r4:bf339ad0
>>> [<c001ad38>] (warn_slowpath_null) from [<bf338744>]
>>> (cppi41_stop_chan+0x1f4/0x378 [cppi41])
>>>  r6:c5e59410 r5:c5e59420 r4:c5feca50
>>> [<bf338550>] (cppi41_stop_chan [cppi41]) from [<bf213dac>]
>>> (cppi41_dma_channel_abort+0xe0/0x2a8 [musb_hdrc])
>>>  r8:c6929180 r7:00000000 r6:c5c67290 r5:bf2175a0 r4:00000008
>>> [<bf213ccc>] (cppi41_dma_channel_abort [musb_hdrc]) from [<bf20c4bc>]
>>> (musb_cleanup_urb+0x60/0x210 [musb_hdrc])
>>>  r10:00000001 r9:c5fca010 r8:c5c67290 r7:a0000093 r6:00000080 r5:c55b5100
>>>  r4:c5fca5a8
>>> [<bf20c45c>] (musb_cleanup_urb [musb_hdrc]) from [<bf20ca8c>]
>>> (musb_urb_dequeue+0xfc/0x164 [musb_hdrc])
>>>  r10:00000001 r9:40408280 r8:c5fca010 r7:a0000093 r6:00000000 r5:c55b5380
>>>  r4:c55b5100
>>> [<bf20c990>] (musb_urb_dequeue [musb_hdrc]) from [<bf10fd7c>]
>>> (unlink1+0x34/0x13c [usbcore])
>>>  r10:00000100 r9:c5cb2a00 r8:c55b5100 r7:ffffff94 r6:c5c6c000 r5:c5dd2380
>>>  r4:c55b5100 r3:bf20c990
>>> [<bf10fd48>] (unlink1 [usbcore]) from [<bf112424>]
>>> (usb_hcd_flush_endpoint+0x164/0x1a4 [usbcore])
>>>  r9:c5cb2a00 r8:c55b5100 r7:c5c6c000 r6:c5dd2398 r5:c5dd2380 r4:ffffe000
>>> [<bf1122c0>] (usb_hcd_flush_endpoint [usbcore]) from [<bf11563c>]
>>> (usb_disable_endpoint+0x50/0x94 [usbcore])
>>>  r9:c5cb2a00 r8:bf39e898 r7:00000000 r6:c5c43000 r5:c5c43000 r4:c5dd2380
>>> [<bf1155ec>] (usb_disable_endpoint [usbcore]) from [<bf1156c4>]
>>> (usb_disable_interface+0x44/0x58 [usbcore])
>>>  r5:c5dd2348 r4:00000000
>>> [<bf115680>] (usb_disable_interface [usbcore]) from [<bf118044>]
>>> (usb_unbind_interface+0x1c0/0x268 [usbcore])
>>>  r7:c5cb2c00 r6:bf39e898 r5:c5cb2c20 r4:c5cb2c20
>>> [<bf117e84>] (usb_unbind_interface [usbcore]) from [<c02ce180>]
>>> (device_release_driver_internal+0x160/0x208)
>>>  r10:00000100 r9:c5cb2a00 r8:00000034 r7:00000000 r6:bf39e898 r5:c5cb2c54
>>>  r4:c5cb2c20
>>> [<c02ce020>] (device_release_driver_internal) from [<c02ce240>]
>>> (device_release_driver+0x18/0x1c)
>>>  r9:c5cb2a00 r8:c05f1008 r7:c5c43070 r6:bf12895c r5:c5cb2c20 r4:c5dc91ac
>>> [<c02ce228>] (device_release_driver) from [<c02ccf70>]
>>> (bus_remove_device+0xd0/0x100)
>>> [<c02ccea0>] (bus_remove_device) from [<c02c9c60>] (device_del+0x120/0x378)
>>>  r7:c5c43070 r6:c5cb2c28 r5:00000000 r4:c5cb2c20
>>> [<c02c9b40>] (device_del) from [<bf11576c>]
>>> (usb_disable_device+0x94/0x1d8 [usbcore])
>>>  r10:00000100 r9:c5cb2a00 r8:c5cb2c00 r7:c5c6c000 r6:00000001 r5:00000000
>>>  r4:c5c43000
>>> [<bf1156d8>] (usb_disable_device [usbcore]) from [<bf10bccc>]
>>> (usb_disconnect+0xb4/0x244 [usbcore])
>>>  r9:c5cb2a00 r8:c5c2d600 r7:c5c430a4 r6:c5c43070 r5:c5c43000 r4:00000000
>>> [<bf10bc18>] (usb_disconnect [usbcore]) from [<bf10d788>]
>>> (hub_event+0x678/0x11dc [usbcore])
>>>  r10:00000100 r9:c05f1008 r8:c5c2dcf8 r7:c68fc400 r6:00000001 r5:40000000
>>>  r4:00000000
>>> [<bf10d110>] (hub_event [usbcore]) from [<c0031db0>]
>>> (process_one_work+0x1d8/0x41c)
>>>  r10:00000008 r9:00000000 r8:c060b1d0 r7:00000000 r6:c7ede200 r5:c6882480
>>>  r4:c5c2dcf8
>>> [<c0031bd8>] (process_one_work) from [<c0032030>] (worker_thread+0x3c/0x670)
>>>  r10:00000008 r9:c060b1e4 r8:c061ab60 r7:c6882498 r6:ffffe000 r5:c060b1d0
>>>  r4:c6882480
>>> [<c0031ff4>] (worker_thread) from [<c0038270>] (kthread+0x134/0x14c)
>>>  r10:c683fe90 r9:c0031ff4 r8:c6882480 r7:c6896000 r6:00000000 r5:c687bd80
>>>  r4:c6803e80
>>> [<c003813c>] (kthread) from [<c00090e0>] (ret_from_fork+0x14/0x34)
>>> Exception stack(0xc6897fb0 to 0xc6897ff8)
>>> 7fa0:                                     00000000 00000000 00000000 00000000
>>> 7fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
>>> 7fe0: 00000000 00000000 00000000 00000000 00000013 00000000
>>>  r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:c003813c
>>>  r4:c687bd80
>>> ---[ end trace cb9c7f93aaa3ed36 ]---
>>> ------------[ cut here ]------------
>>>
>>>
>>> adam
>>>
>>
>> Hi Adam,
>>
>> this is a known issue and it's present in mainline and even in TI BSP.
>> It's been deprioritized for now, but I'll return to debugging it once
>> the common clock conversion is complete.
>>
>> Thanks,
>> Bartosz
>
> Ugh, -ETOOEARLY
>
> I meant the ohci dying during cpufreq bug, not the crash you posted.
>
> Bart

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