Re: brcm 4329 problems

[Arend van Spriel <arend@broadcom.com>]

On 02/10/2014 03:03 PM, Russell King - ARM Linux wrote:
> On Mon, Feb 10, 2014 at 02:50:42PM +0800, Dong Aisheng wrote:
>> On Mon, Feb 10, 2014 at 7:27 AM, Russell King - ARM Linux
>> <linux@arm.linux.org.uk> wrote:
>>> On Sun, Feb 09, 2014 at 08:59:17PM +0000, Russell King - ARM Linux wrote:
>>>> On Sun, Feb 09, 2014 at 10:05:13AM +0100, Arend van Spriel wrote:
>>>>> Yeah. I did not mention this, but indeed the first log you provided
>>>>> already made that clear (to me). In your last log the driver sends an UP
>>>>> command to the firmware on which no response is given. So I was hoping
>>>>> the forensics file (which is firmware console buffer) would show an
>>>>> error message of some kind. Also that is not the case. Have to come up
>>>>> with new ideas about what is going wrong here.
>>>>
>>>> I'm chasing a theory at the moment, but it's being complicated by the
>>>> driver oopsing on unload...
>>>
>>> Theory proven.
>>>
>>> May I first take the time to apologise to Arend for wasting his time with
>>> this issue; the issue is not the Broadcom driver, but the SDHCI driver.
>>>
>>> My theory was that it's the sdhci driver causing the problems...  My
>>> suspicions were first raised when I read through various SDHCI driver
>>> functions such as the set_ios methods when chasing down a problem with
>>> UHS-1 SD cards, and later when I was reading it's interrupt handling
>>> code.
>>>
>>> The driver looks very much like a patchwork quilt of different hacks,
>>> all trying to co-operate with each other in the semblence of something
>>> working - the result is something which does stuff in ways that the SD
>>> card spec doesn't allow, but also does some pretty stupid things when
>>> you have a SDIO device attached.
>>>
>>> The SDIO problems become pretty obvious when you see this log:
>>>
>>> [   51.112923] brcmfmac: brcmf_fil_cmd_int_set cmd=2, value=0
>>> [   51.112937] brcmfmac: brcmf_proto_bcdc_set_dcmd Enter, cmd 2 len 4
>>> [   51.112946] brcmfmac: brcmf_proto_bcdc_msg Enter
>>> [   51.112981] brcmfmac: brcmf_sdio_bus_sleep request WAKE currently WAKE
>>> [   51.112989] brcmfmac: brcmf_sdio_clkctl Enter
>>> [   51.113498] brcmfmac: brcmf_proto_bcdc_cmplt Enter
>>> [   51.128501] brcmfmac: brcmf_sdio_bus_watchdog idle
>>> [   51.128522] brcmfmac: brcmf_sdio_bus_sleep request SLEEP currently WAKE
>>> [   51.128532] brcmfmac: brcmf_sdio_clkctl Enter
>>> [   51.128540] brcmfmac: brcmf_sdio_htclk Enter
>>> [   51.128549] brcmfmac: brcmf_sdiod_regwb addr:0x0001000e, data:0x00
>>> [   51.128560] brcmfmac: brcmf_sdiod_request_data rw=1, func=1, addr=0x1000e, nbytes=1
>>> [   51.128645] brcmfmac: brcmf_sdio_htclk CLKCTL: turned OFF
>>> [   51.128655] brcmfmac: brcmf_sdio_sdclk Enter
>>> [   51.128667] brcmfmac: brcmf_sdio_clkctl 3 -> 0
>>> [   51.180385] mmc0: runtime suspend
>>> [   53.112272] brcmfmac: brcmf_sdio_bus_rxctl: resumed on timeout
>>> [   53.118290] brcmfmac: brcmf_sdio_bus_sleep request WAKE currently WAKE
>>> [   53.118302] brcmfmac: brcmf_sdio_clkctl Enter
>>> [   53.118312] brcmfmac: brcmf_sdio_sdclk Enter
>>> [   53.118319] brcmfmac: brcmf_sdio_htclk Enter
>>> [   53.118329] brcmfmac: brcmf_sdiod_regwb addr:0x0001000e, data:0x10
>>> [   53.118341] brcmfmac: brcmf_sdiod_request_data rw=1, func=1, addr=0x1000e, nbytes=1
>>> [   53.118537] sdhci-esdhc-imx 2190000.usdhc: desired SD clock: 50000000, actual: 49500000
>>> [   53.118550] mmc0: esdhc_pltfm_set_clock: CLK on
>>> [   53.119723] sdhci-esdhc-imx 2190000.usdhc: change pinctrl state for uhs 0
>>> [   53.125880] mmc0: sdio irq enabled: 007f0003 007f0003
>>> [   53.125898] mmc0: runtime resume
>>> [   53.125910] mmc0: card irq raised
>>> [   53.125925] mmc0: sdio irq disabled: 007f0103 007f0103
>>> [   53.126030] brcmfmac: brcmf_sdiod_regrb addr:0x0001000e
>>> [   53.126055] brcmfmac: brcmf_sdiod_request_data rw=0, func=1, addr=0x1000e, nbytes=1
>>>
>>> The values printed in "sdio irq *abled" are the INT_ENABLE and SIGNAL_ENABLE
>>> register values immediately before the stated action is taken bit 8 is
>>> the interrupt enable for card interrupts.  Earlier in the log, SDIO card
>>> interrupts were enabled (one was handled immediately before the above
>>> broadcom cmd=2 message was sent.
>>>
>>> Yep, that's right - at 51.180385, the SDIO host has /all/ interrupts
>>> disabled by a runtime suspend - including any interrupt from the card.
>>> The brcmfmac driver times out after 2 seconds having sent the "up"
>>> command, and re-awakens the host, which is runtime resumed at 53.125898,
>>> enabling the SDIO card interrupt at that time.
>>>
>>> And lo and behold - the card has an interrupt pending!  Too bad, we're
>>> too late for the driver to forward the interrupt to the SDIO interrupt
>>> thread and get it to the driver before the time-out is processed.
>>>
>>> Here's the proof - the above messages came from:
>>>
>>> int sdhci_runtime_suspend_host(struct sdhci_host *host)
>>> {
>>>         unsigned long flags;
>>>         int ret = 0;
>>>
>>> printk(KERN_DEBUG "%s: runtime suspend\n",
>>>         mmc_hostname(host->mmc));
>>> ...
>>>         spin_lock_irqsave(&host->lock, flags);
>>>         sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
>>>         spin_unlock_irqrestore(&host->lock, flags);
>>>
>>> int sdhci_runtime_resume_host(struct sdhci_host *host)
>>> {
>>>         unsigned long flags;
>>>         int ret = 0, host_flags = host->flags;
>>> ...
>>>         /* Enable SDIO IRQ */
>>>         if ((host->flags & SDHCI_SDIO_IRQ_ENABLED))
>>>                 sdhci_enable_sdio_irq_nolock(host, true);
>>>
>>>         /* Enable Card Detection */
>>>         sdhci_enable_card_detection(host);
>>>
>>> printk(KERN_DEBUG "%s: runtime resume\n",
>>>         mmc_hostname(host->mmc));
>>>         spin_unlock_irqrestore(&host->lock, flags);
>>>
>>>         return ret;
>>> }
>>> EXPORT_SYMBOL_GPL(sdhci_runtime_resume_host);
>>>
>>> To me, it looks like SDHCI needs a major rework...  And there needs to
>>> be some recognition that - maybe - leaving SDIO interrupts enabled even
>>> though we may want the host to enter a low power mode is something that's
>>> really very very desirable...
>>>
>>
>> I'm not quite clear about your issue.
>> But it seems your issue is caused by runtime pm disabling the
>> interrupt & clocks as you said.
>>
>> Can you try the patch i mentioned here:
>> http://www.spinics.net/lists/linux-mmc/msg24764.html
>>
>> That will prevent the host to do runtime pm for SDIO devices.
> 
> Why not allow runtime PM at the host level, but still allow the
> interrupt to be received?  Doesn't it make sense to allow PM even with
> SDIO cards in place?
> 
> Once I get imx-drm off my plate, I'm going to put some work into
> rewriting the sdhci driver mess in a much cleaner way - we can't go on
> putting hacks on top of what's already there, it's already a total mess.

You have my vote on that ;-) Just not sure whether you can keep it
limited to sdhci. Ah, well. I will keep an eye (or two) on the mmc list.

Regards,
Arend