On Mon, Feb 10, 2014 at 11:25 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> On 10 February 2014 15:03, Russell King - ARM Linux
> <linux@xxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxx> 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?
>
> Agree. Just for your reference, there has been related discussions on
> the mmc list for how to solve this for host drivers.
>
> This is a patchset for omap_hsmmc, though I don't think the maintainer
> has picked it up yet.
> http://www.spinics.net/lists/linux-omap/msg101469.html
>
> Typically, once the host becomes runtime suspended, you need re-route
> the DAT1 line to a GPIO irq to continue to get the irqs.
>
That seems a way out.
But what if the card can not send interrupt to host without clock?
Then can this still work?
Regards
Dong Aisheng
> Kind regards
> Ulf Hansson
>
>>
>> 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.
>>
>> --
>> FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation
>> in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad.
>> Estimate before purchase was "up to 13.2Mbit".
>> --
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