Re: [BUG] SPD5118 Intermittent MR11 Corruption During Suspend/Resume

[Matthew Bettencourt]

Hello Guetner,

I believe I implemented the print port correctly, below is the dmesg and 
piix4_sb800_port_sel() function.

> Another idea might be to decode the ACPI data and see if there is 
anything
> in there which accesses the SMBus controller.

I have no problem grabbing the ACPI data or whatever is needed, just 
might need a little bit of guidance on that front. I am OK at c code 
with some AI help but never really delved into ACPI.

And one last thing I greatly appreciate all the time and effort you are 
putting into this. I would definitely not have been able to get this far 
without your help.

--- CMD=0b
[19462.122064] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.123074] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.123109] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.124081] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.124115] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.125067] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.125074] [  T21668] spd5118 12-0053: PRE BIT UPDATE: SUSPEND MR11 
(0x0B) -> Cache: 0x00 | Bus: 0x00
[19462.125094] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.126064] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.126072] [  T21683] spd5118 12-0051: PRE BIT UPDATE: SUSPEND MR11 
(0x0B) -> Cache: 0x00 | Bus: 0x00
[19462.126088] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.127545] [  T21668] i2c i2c-12: [PIIX4 ERROR TRACE TRIGGERED] result=0
                        STEP 1 (PRE-START)    : CNT=08, CMD=0b, ADD=a7, 
DAT0=00, DAT1=18
                        STEP 2 (START BIT SET): CNT=08, CMD=0b, ADD=a7, 
DAT0=00, DAT1=18
                        STEP 3 (POST-WAIT)    : STS=00, CNT=08, CMD=01, 
ADD=45, DAT0=ff, DAT1=18
                        STEP 4 (POST-CLEANUP) : CNT=08, CMD=01, ADD=45, 
DAT0=ff, DAT1=18
[19462.127556] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.127582] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.128217] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.128240] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.128894] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.128920] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.129561] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.129588] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.130227] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.130255] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.130894] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.130919] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.131560] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.131584] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.132226] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.132249] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.132882] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.132904] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.133555] [  T21683] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.133563] [  T21683] spd5118 12-0051: POST BIT UPDATE: SUSPEND MR11 
(0x0B) -> Cache: 0x00 | Bus: 0x00
[19462.133581] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.134238] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19462.134244] [  T21668] spd5118 12-0053: POST BIT UPDATE: SUSPEND MR11 
(0x0B) -> Cache: 0x00 | Bus: 0x08

--- CMD=1a
[19664.445821] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.446491] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.446531] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.447201] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.447235] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.447890] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.447903] [  T21712] spd5118 12-0053: PRE BIT UPDATE: SUSPEND MR11 
(0x0B) -> Cache: 0x00 | Bus: 0x00
[19664.447923] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.448574] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.448581] [  T21668] spd5118 12-0051: PRE BIT UPDATE: SUSPEND MR11 
(0x0B) -> Cache: 0x00 | Bus: 0x00
[19664.448601] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.449239] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.449264] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.449886] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.449910] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.451402] [  T21712] i2c i2c-12: [PIIX4 ERROR TRACE TRIGGERED] result=0
                            STEP 1 (PRE-START)    : CNT=08, CMD=1a, 
ADD=a7, DAT0=00, DAT1=18
                            STEP 2 (START BIT SET): CNT=08, CMD=1a, 
ADD=a7, DAT0=00, DAT1=18
                            STEP 3 (POST-WAIT)    : STS=00, CNT=08, 
CMD=01, ADD=45, DAT0=ff, DAT1=18
                            STEP 4 (POST-CLEANUP) : CNT=08, CMD=01, 
ADD=45, DAT0=ff, DAT1=18
[19664.451414] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.451438] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.452398] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.452423] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.453393] [  T21712] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.453400] [  T21712] spd5118 12-0053: POST BIT UPDATE: SUSPEND MR11 
(0x0B) -> Cache: 0x00 | Bus: 0x00
[19664.453417] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.454396] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.454417] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.454883] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.454904] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.455541] [  T21668] piix4_smbus: PORT SEL -> requested=0x00 | 
hardware_was=0x00 | writing=0x07
[19664.455549] [  T21668] spd5118 12-0051: POST BIT UPDATE: SUSPEND MR11 
(0x0B) -> Cache: 0x00 | Bus: 0x00


---
int piix4_sb800_port_sel(u8 port, struct sb800_mmio_cfg *mmio_cfg)
{
    u8 smba_en_lo, val, prev_port;

    if (mmio_cfg->use_mmio) {
        smba_en_lo = ioread8(mmio_cfg->addr + piix4_port_sel_sb800);
        val = (smba_en_lo & ~piix4_port_mask_sb800) | port;
        if (smba_en_lo != val)
            iowrite8(val, mmio_cfg->addr + piix4_port_sel_sb800);

        prev_port = smba_en_lo & piix4_port_mask_sb800;
    } else {
        outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
        smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);

        val = (smba_en_lo & ~piix4_port_mask_sb800) | port;
        if (smba_en_lo != val)
            outb_p(val, SB800_PIIX4_SMB_IDX + 1);

        prev_port = smba_en_lo & piix4_port_mask_sb800;
    }

    /* Always print port state on every function call */
    pr_info("piix4_smbus: PORT SEL -> requested=0x%02x | 
hardware_was=0x%02x | writing=0x%02x\n",
            port, prev_port, val);

    return prev_port;
}


Thanks,
Matthew
On 9/1/26 8:32 PM, Guenter Roeck wrote:
> On 9/1/26 17:57, Matthew Bettencourt wrote:
> > Hello Guenter,
> >
> > These are the only boot up messages I see for SMBus/i2c/piix4
> >
> > [    1.848113] [    T272] i2c_dev: i2c /dev entries driver
> > [    6.093885] [    T727] piix4_smbus 0000:00:14.0: SMBus Host 
> > Controller at 0xb00, revision 0
> > [    6.093888] [    T727] piix4_smbus 0000:00:14.0: Using register 
> > 0x02 for SMBus port selection
>
> So bus 12 and 13 share the same controller address.
>
> There is one more thing we can try: Print the selected port before and 
> after
> the access. The code to access the port number is in 
> piix4_sb800_port_sel().
> If we are "lucky", we may find that the selected port changed.
>
> Unfortunately that isn't going to help much since we'd still have
> to figure out where that happens.
>
> Another idea might be to decode the ACPI data and see if there is anything
> in there which accesses the SMBus controller.
>
> Thanks,
> Guenter
>
> > [    6.095020] [    T727] i2c i2c-12: Successfully instantiated SPD at 
> > 0x51
> > [    6.095981] [    T727] i2c i2c-12: Successfully instantiated SPD at 
> > 0x53
> > [    6.096039] [    T727] piix4_smbus 0000:00:14.0: Auxiliary SMBus 
> > Host Controller at 0xb20
> >
> >
> > I don't see anything on bus 13 or 14, I added 10-12 as well for good 
> > measure.
> > # sudo i2cdetect -y -a 14
> >       0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
> > 00: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 70: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > # sudo i2cdetect -y -a 13
> >       0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
> > 00: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 70: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > # sudo i2cdetect -y -a 12
> >       0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
> > 00: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 10: -- -- -- -- -- 15 -- -- -- -- -- -- -- -- -- --
> > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 40: -- -- -- -- -- -- -- -- -- 49 -- 4b -- -- -- --
> > 50: -- 51 -- 53 -- -- -- -- -- -- -- -- -- -- -- --
> > 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 70: -- 71 -- 73 -- -- -- -- -- -- -- -- -- -- 7e --
> > # sudo i2cdetect -y -a 11
> >       0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
> > 00: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 30: 30 -- -- -- -- -- -- 37 -- -- -- -- -- -- -- --
> > 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 50: 50 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 70: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > # sudo i2cdetect -y -a 10
> >       0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
> > 00: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
> > 70: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --