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.
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.
>
> --
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> Estimate before purchase was "up to 13.2Mbit".
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