Re: Rock64 configuration fails to boot for main 22c4ab6cb015 but worked for main 06bd74e1e39c (Nov 21): e.MMC mishandled?

From: Mark Millard via freebsd-arm <freebsd-arm_at_freebsd.org>
Date: Sun, 12 Dec 2021 21:38:19 UTC
On 2021-Dec-12, at 00:59, Mark Millard <marklmi@yahoo.com> wrote:

> On 2021-Dec-12, at 00:29, Mark Millard via freebsd-arm <freebsd-arm@freebsd.org> wrote:
> 
>> On 2021-Dec-11, at 16:19, Mark Millard <marklmi@yahoo.com> wrote:
>> 
>>> [I've cut out the history: just presenting some new evidence.]
>>> 
>>> First, a little context from getting to the db> prompt.
>>> 
>>> db> ps
>>> pid  ppid  pgrp   uid  state   wmesg   wchan               cmd
>>> 18     0     0     0  DL      syncer  0xffff000000eca5a8  [syncer]
>>> 17     0     0     0  DL      vlruwt  0xffffa00007d2ea60  [vnlru]
>>> 16     0     0     0  DL      (threaded)                  [bufdaemon]
>>> 100089                   D       qsleep  0xffff000000ec9478  [bufdaemon]
>>> 100092                   D       -       0xffff000000c11100  [bufspacedaemon-0]
>>> 100093                   D       -       0xffff000000c21680  [bufspacedaemon-1]
>>>  9     0     0     0  DL      psleep  0xffff000000ef0650  [vmdaemon]
>>>  8     0     0     0  DL      (threaded)                  [pagedaemon]
>>> 100087                   D       psleep  0xffff000000ee2b38  [dom0]
>>> 100094                   D       launds  0xffff000000ee2b44  [laundry: dom0]
>>> 100095                   D       umarcl  0xffff0000007b38d8  [uma]
>>>  7     0     0     0  DL      mmcsd d 0xffffa00007b72e00  [mmcsd0boot1: mmc/sd]
>>>  6     0     0     0  DL      mmcsd d 0xffffa00007b71300  [mmcsd0boot0: mmc/sd]
>>>  5     0     0     0  DL      mmcreq  0xffff00009b5d0710  [mmcsd0: mmc/sd card]
>>>  4     0     0     0  DL      -       0xffff000000ccc020  [rand_harvestq]
>>> 15     0     0     0  DL      (threaded)                  [usb]
>>> . . .
>>> 
>>> and "mmcreq" is from the while loop in:
>>> 
>>> static int
>>> mmc_wait_for_req(struct mmc_softc *sc, struct mmc_request *req)
>>> {
>>> 
>>>      req->done = mmc_wakeup;
>>>      req->done_data = sc;
>>>      if (__predict_false(mmc_debug > 1)) {
>>>              device_printf(sc->dev, "REQUEST: CMD%d arg %#x flags %#x",
>>>                  req->cmd->opcode, req->cmd->arg, req->cmd->flags);     
>>>              if (req->cmd->data) {
>>>                      printf(" data %d\n", (int)req->cmd->data->len); 
>>>              } else
>>>                      printf("\n");
>>>      }
>>>      MMCBR_REQUEST(device_get_parent(sc->dev), sc->dev, req);
>>>      MMC_LOCK(sc);
>>>      while ((req->flags & MMC_REQ_DONE) == 0)
>>>              msleep(req, &sc->sc_mtx, 0, "mmcreq", 0);
>>>      MMC_UNLOCK(sc);
>>>      if (__predict_false(mmc_debug > 2 || (mmc_debug > 0 &&
>>>          req->cmd->error != MMC_ERR_NONE)))
>>>              device_printf(sc->dev, "CMD%d RESULT: %d\n",
>>>                  req->cmd->opcode, req->cmd->error);
>>>      return (0);
>>> }
>>> 
>>> So it appears that the error report:
>>> 
>>> mmcsd0: Error indicated: 4 Failed
>>> 
>>> ends up associated with (req->flags & MMC_REQ_DONE) == 0 staying
>>> true in the above code: an unbounded loop with MMC_LOCK(sc) active.
>>> The "4" in the error report seems to be from:
>>> 
>>> #define MMC_ERR_FAILED  4
>>> 
>>> It looks like there are some problems with handling errors, problems
>>> such that it gets stuck looping (no panic, no progress).
>>> 
>>> That seems to be separate from why the MMC_ERR_FAILED was generated
>>> in the first place. So: 2 problems, not just one. Thus it may be a
>>> good context for tackling the looping problem with a known example
>>> failure to look at.
>>> 
>>> 
>>> 
>>> Just for reference, I tried "boot -v" with debug.verbose_sysinit=1 in place,
>>> just to capture and report the tail of the output for the boot failure.
>>> 
>>> . . .
>>> subsystem f000000
>>> release_aps(0)... Release APs...done
>>> done.
>>> intr_irq_shuffle(0)... Trying to mount root from ufs:/dev/gpt/Rock64root []...
>>> done.
>>> netisr_start(0)... done.
>>> taskqgroup_bind_softirq(0)... done.
>>> GEOM: new disk mmcsd0
>>> GEOM: new disk mmcsd0boot0
>>> GEOM: new disk mmcsd0boot1
>>> smp_after_idle_runnable(0)... done.
>>> taskqgroup_bind_if_config_tqg(0)... done.
>>> taskqgroup_bind_if_io_tqg(0)... done.
>>> tmr_setup_user_access(0)... done.
>>> subsystem f000001
>>> mmcsd0: Error indicated: 4 Failed
>>> epoch_init_smp(0)... done.
>>> subsystem f100000
>>> racctd_init(0)... done.
>>> subsystem fffffff
>>> start_periodic_resettodr(0)... done.
>>> oktousecallout(0)... done.
>>> clknode_finish(0)... Unresolved linked clock found: hdmi_phy
>>> Unresolved linked clock found: usb480m_phy
>>> done.
>>> regulator_constraint(0)... done.
>>> regulator_shutdown(0)... regulator: shutting down unused regulators
>>> regulator: shutting down vcc_sd... busy
>>> done.
>>> uhub0: 1 port with 1 removable, self powered
>>> uhub2: 2 ports with 2 removable, self powered
>>> uhub3: 1 port with 1 removable, self powered
>>> uhub1: 1 port with 1 removable, self powered
>>> ugen4.2: <Samsung PSSD T7 Touch> at usbus4
>>> umass0 on uhub2
>>> umass0: <Samsung PSSD T7 Touch, class 0/0, rev 3.20/1.00, addr 1> on usbus4
>>> umass0:  SCSI over Bulk-Only; quirks = 0x0000
>>> umass0:0:0: Attached to scbus0
>>> pass0 at umass-sim0 bus 0 scbus0 target 0 lun 0
>>> pass0: <Samsung PSSD T7 Touch 0> Fixed Direct Access SPC-4 SCSI device
>>> pass0: Serial Number REPLACED
>>> pass0: 400.000MB/s transfers
>>> da0 at umass-sim0 bus 0 scbus0 target 0 lun 0
>>> da0: <Samsung PSSD T7 Touch 0> Fixed Direct Access SPC-4 SCSI device
>>> da0: Serial Number REPLACED
>>> da0: 400.000MB/s transfers
>>> da0: 953869MB (1953525168 512 byte sectors)
>>> da0: quirks=0x2<NO_6_BYTE>
>>> da0: Delete methods: <NONE(*),ZERO>
>>> random: unblocking device.
>>> 
>>> No more output after that.
>> 
>> As for why MMC_ERR_FAILED results, the following code diff is
>> intended to suggest what I think may be incomplete about sticking
>> to what the device-specific code supports vs. does not support
>> (not supporting HS200 here). The code does compile in my context
>> but is untested.
> 
> It is now tested (at least to be a useful hack): no longer am I
> running an older 1400042 kernel. For reference,
> 
> # uname -apKU
> FreeBSD Rock64_RPi_4_3_2v1p2 14.0-CURRENT FreeBSD 14.0-CURRENT #18 main-n251456-22c4ab6cb015-dirty: Sun Dec 12 00:34:53 PST 2021     root@CA72_16Gp_ZFS:/usr/obj/BUILDs/main-CA53-nodbg-clang/usr/main-src/arm64.aarch64/sys/GENERIC-NODBG-CA53  arm64 aarch64 1400043 1400043
> 
> And it reports during the boot (other than the "REPLACED"):
> 
> mmcsd0: 125GB <MMCHC DJNB4R 0.7 SN REPLACED MFG 06/2016 by 21 0x0000> at mmc0 52.0MHz/8bit/1016-block
> 
> So it no longer sets up a mode that the rk3328-specific-code does not
> actually support.
> 
> (Nothing that I've done here deals with the looping issue when there
> is a MMC_ERR_FAILED or the like.)
> 
>> The email handling may mess up some leading
>> whitespace --but, again, I'm only trying to suggest a type of
>> change.
>> 
>> # git -C /usr/main-src/ diff /usr/main-src/sys/dev/mmc
>> diff --git a/sys/dev/mmc/mmc.c b/sys/dev/mmc/mmc.c
>> index 9c73dfd57ce0..dffd1c382684 100644
>> --- a/sys/dev/mmc/mmc.c
>> +++ b/sys/dev/mmc/mmc.c
>> @@ -59,6 +59,7 @@ __FBSDID("$FreeBSD$");
>> #include <sys/param.h>
>> #include <sys/systm.h>
>> #include <sys/kernel.h>
>> +#include <sys/kobj.h>
>> #include <sys/malloc.h>
>> #include <sys/lock.h>
>> #include <sys/module.h>
>> @@ -1512,6 +1513,8 @@ mmc_timing_to_string(enum mmc_bus_timing timing)
>> static bool
>> mmc_host_timing(device_t dev, enum mmc_bus_timing timing)
>> {
>> +       kobjop_desc_t kobj_desc;
>> +       kobj_method_t *kobj_method;
>>       int host_caps;
>> 
>>       host_caps = mmcbr_get_caps(dev);
>> @@ -1543,14 +1546,37 @@ mmc_host_timing(device_t dev, enum mmc_bus_timing timing)
>>       case bus_timing_mmc_ddr52:
>>               return (HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_DDR52));
>>       case bus_timing_mmc_hs200:
>> -               return (HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS200_120) ||
>> -                       HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS200_180));
>>       case bus_timing_mmc_hs400:
>> -               return (HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS400_120) ||
>> -                       HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS400_180));
>>       case bus_timing_mmc_hs400es:
>> -               return (HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS400 |
>> -                   MMC_CAP_MMC_ENH_STROBE));
>> +               /*
>> +                * Disable eMMC modes that require use of
>> +                * MMC_SEND_TUNING_BLOCK_HS200 to set things up if either the
>> +                * tune or re-tune method is the default NULL implementation.
>> +                */
>> +               kobj_desc = &mmcbr_tune_desc;
>> +               kobj_method = kobj_lookup_method(((kobj_t)dev)->ops->cls, NULL,
>> +                   kobj_desc);
>> +               if (kobj_method == &kobj_desc->deflt)
>> +                       return (false);
>> +               kobj_desc = &mmcbr_retune_desc;
>> +               kobj_method = kobj_lookup_method(((kobj_t)dev)->ops->cls, NULL,
>> +                   kobj_desc);
>> +               if (kobj_method == &kobj_desc->deflt) {
>> +                       return (false);
>> +               }
>> +
>> +               /*
>> +                * Otherwise track the host capabilities.
>> +                */
>> +               if (timing == bus_timing_mmc_hs200)
>> +                       return (HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS200_120) ||
>> +                               HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS200_180));
>> +               if (timing == bus_timing_mmc_hs400)
>> +                       return (HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS400_120) ||
>> +                               HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS400_180));
>> +               if (timing == bus_timing_mmc_hs400es)
>> +                       return (HOST_TIMING_CAP(host_caps, MMC_CAP_MMC_HS400 |
>> +                               MMC_CAP_MMC_ENH_STROBE));
>>       }
>> 
>> #undef HOST_TIMING_CAP
>> 
>> 
>> In other words: have mmc_host_timing avoid returning true for some
>> combinations that definitely do not have sufficient software support
>> present at the time. (So far as I can tell, the rk3328's get the
>> NULL-implementations as things are.)
>> 
>> I expect that this sort of thing would go back to using
>> MMC_CAP_MMC_DDR52 for the rk3328's, as an example. Working, but in a
>> slower mode, the same mode as FreeBSD was previously using.
>> 
>> A possible incompleteness in the suggestion is that there is also a
>> drive-strength setting involved. If that also had "kobj" interfacing
>> and NULL-implementation possibilities, then in the future there would
>> be more to test for possibly forcing return-false than I did above.
>> 
>> Hopefully this sort of thing would help, possibly more than just for
>> rk3328's.
> 
> 

As for what was happening without my patch . . .

sys/dev/mmc/mmcbr_if.m defines:

        static int
        null_retune(device_t brdev __unused, device_t reqdev __unused,
            bool reset __unused)
        {

                return (0);
        }

        static int
        null_tune(device_t brdev __unused, device_t reqdev __unused,
            bool hs400 __unused)
        {

                return (0);
        }
. . .
#
# Called by the mmcbus with the bridge claimed to execute initial tuning.
#
METHOD int tune {
        device_t        brdev;
        device_t        reqdev;
        bool            hs400;
} DEFAULT null_tune;

#
# Called by the mmcbus with the bridge claimed to execute re-tuning.
#
METHOD int retune {
        device_t        brdev;
        device_t        reqdev;
        bool            reset;
} DEFAULT null_retune;
. . .

It is these success-reporting no-op routines that were being
used to attempt the tuning: so there was no tuning done.

The code that I added detects that these routines would be
used and avoids allowing contexts that would involve putting
them to use with HS200 mode.

I'll note that there is another such null_* routine that the
code (even with my patch) does not deal with avoiding the use
of:

. . .
        static int
        null_switch_vccq(device_t brdev __unused, device_t reqdev __unused)
        {

                return (0);
        }
. . .
#
# Called by the mmcbus to switch the signaling voltage (VCCQ).
#
METHOD int switch_vccq {
        device_t        brdev;
        device_t        reqdev;
} DEFAULT null_switch_vccq;
. . .

/usr/main-src/sys/dev/sdhci/sdhci.c has somewhat analogous code for
somewhat analogous null_* routines. null_set_uhs_timing for that is
from sys/dev/sdhci/sdhci_if.m (but the other two are again the above
null_tune and null_retune routines, so not repeated here):

. . .
        static void
        null_set_uhs_timing(device_t brdev __unused,
            struct sdhci_slot *slot __unused)
        {

        }
. . .
METHOD void set_uhs_timing {
        device_t                brdev;
        struct sdhci_slot       *slot;
} DEFAULT null_set_uhs_timing;
. . .

sdhci_init_slot(device_t dev, struct sdhci_slot *slot, int num)
in sdhci.c looks like (in part):

. . .
        /*
         * Disable UHS-I and eMMC modes if the set_uhs_timing method is the
         * default NULL implementation.
         */
        kobj_desc = &sdhci_set_uhs_timing_desc;
        kobj_method = kobj_lookup_method(((kobj_t)dev)->ops->cls, NULL,
            kobj_desc);
        if (kobj_method == &kobj_desc->deflt)
                host_caps &= ~(MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
                    MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_DDR50 | MMC_CAP_UHS_SDR104 |
                    MMC_CAP_MMC_DDR52 | MMC_CAP_MMC_HS200 | MMC_CAP_MMC_HS400);

#define SDHCI_CAP_MODES_TUNING(caps2)                                   \
    (((caps2) & SDHCI_TUNE_SDR50 ? MMC_CAP_UHS_SDR50 : 0) |             \
    MMC_CAP_UHS_DDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_MMC_HS200 |        \
    MMC_CAP_MMC_HS400)
           
        /*
         * Disable UHS-I and eMMC modes that require (re-)tuning if either
         * the tune or re-tune method is the default NULL implementation.
         */
        kobj_desc = &mmcbr_tune_desc;       
        kobj_method = kobj_lookup_method(((kobj_t)dev)->ops->cls, NULL,
            kobj_desc);
        if (kobj_method == &kobj_desc->deflt)
                goto no_tuning;
        kobj_desc = &mmcbr_retune_desc;    
        kobj_method = kobj_lookup_method(((kobj_t)dev)->ops->cls, NULL,
            kobj_desc);
        if (kobj_method == &kobj_desc->deflt) {
no_tuning:
                host_caps &= ~(SDHCI_CAP_MODES_TUNING(caps2));
        }
. . .

What I've done in my patch is analogous to what the the code shown
after the #define SDHCI_CAP_MODES_TUNING above does, translated to
fit the mmc's pre-existing code structure.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)