From: Matthew Bettencourt <matthew.bettencourt@gmail.com>
To: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [BUG] SPD5118 Intermittent MR11 Corruption During Suspend/Resume
Date: Wed, 2 Sep 2026 09:00:24 -0500 [thread overview]
Message-ID: <9cdf4b63-8f99-4a80-b0be-3f3df69e526e@gmail.com> (raw)
In-Reply-To: <a953dcaa-cfff-40c8-85a9-c12601e49e85@roeck-us.net>
Hello Guenter,
> It would be something like
>
> sudo acpidump > acpi.log
> acpixtract acpi.log
> iasl -d *.dat
>
> You'll get a number of.dsl files with cryptic assembler-style
> code and data. Then the digging starts ... you may find something
> like "Name (SMB0, 0x0B00)" in dsdt.dsl. Then we can only hope to
> figure out if ACPI actually accesses it.
That wasn't as hard as I thought. I got everything decoding I guess, I
just did a grep on all the dsl files for SMB.
$ grep -i -rn "SMB" *.dsl
dsdt.dsl:295: Name (SMBB, 0x0B20)
dsdt.dsl:296: Name (SMBL, 0x20)
dsdt.dsl:297: Name (SMB0, 0x0B00)
dsdt.dsl:298: Name (SMBM, 0x10)
dsdt.dsl:311: Name (SSMB, 0xFED80200)
dsdt.dsl:3352: If (SMBB)
dsdt.dsl:3354: CreateWordField (CRS,
0xD2, SMB1)
dsdt.dsl:3357: SMB1 = SMBB /* \SMBB */
dsdt.dsl:3358: SMH1 = SMBB /* \SMBB */
dsdt.dsl:3359: SML1 = SMBL /* \SMBL */
dsdt.dsl:3360: CreateWordField (CRS,
0xCA, SMBZ)
dsdt.dsl:3363: SMBZ = SMB0 /* \SMB0 */
dsdt.dsl:3364: SMH0 = SMB0 /* \SMB0 */
dsdt.dsl:3365: SML0 = SMBM /* \SMBM */
ssdt4.dsl:4026: SMB8, 8
ssdt4.dsl:4032: SMB8 |= 0x40
ssdt4.dsl:4046: Local1 = SMB8 /* \M477.SMB8 */
ssdt4.dsl:4062: SMB8, 8
ssdt4.dsl:4065: SMB8 |= 0x80
ssdt4.dsl:4073: SMB0, 8,
ssdt4.dsl:4074: SMB1, 8,
ssdt4.dsl:4075: SMB2, 8
ssdt4.dsl:4085: SMB0 = 0x1F
ssdt4.dsl:4100: Local2 = SMB0 /* \M479.SMB0 */
ssdt4.dsl:4105: SMB2 = 0x02
ssdt4.dsl:4113: If (((SMB0 & One) != Zero))
ssdt4.dsl:4124: SMB1 = 0x3F
ssdt4.dsl:4139: Local2 = SMB1 /* \M479.SMB1 */
ssdt4.dsl:4144: SMB1 = 0x02
ssdt4.dsl:4152: If (((SMB1 & One) != Zero))
ssdt4.dsl:4173: M460 (" KER-ASL-CpmSmbusExecutor (Port%d, isRead
%d, Potcl %d, DevAddr 0x%X, Cmd 0x%X)\n", Arg0, Arg1, Arg2, Arg3, Arg4,
Zero)
ssdt4.dsl:4179: M459 (" KER-ASL-CpmSmbusExecutor return
0x80\n", Zero)
ssdt4.dsl:4186: M459 (" KER-ASL-CpmSmbusExecutor return
0x81\n", Zero)
ssdt4.dsl:4201: M459 (" KER-ASL-CpmSmbusExecutor return
0x82\n", Zero)
ssdt4.dsl:4212: M460 (" KER-ASL-CpmSmbusExecutor return
0x83, Length %d\n", Local2, Zero, Zero, Zero, Zero, Zero)
ssdt4.dsl:4223: M460 (" KER-ASL-CpmSmbusExecutor return
0x84, Local4 %d\n", Local4, Zero, Zero, Zero, Zero, Zero)
ssdt4.dsl:4230: SMB0, 8,
ssdt4.dsl:4231: SMB1, 8,
ssdt4.dsl:4232: SMB2, 8,
ssdt4.dsl:4233: SMB3, 8,
ssdt4.dsl:4234: SMB4, 8,
ssdt4.dsl:4235: SMB5, 8,
ssdt4.dsl:4236: SMB6, 8,
ssdt4.dsl:4237: SMB7, 8,
ssdt4.dsl:4238: SMB8, 8
ssdt4.dsl:4249: Local6 = SMB2 /* \M47A.SMB2 */
ssdt4.dsl:4250: SMB2 = (Local6 & 0x7F)
ssdt4.dsl:4257: SMB2 = Local6
ssdt4.dsl:4267: M459 (" KER-ASL-CpmSmbusExecutor return
0x85\n", Zero)
ssdt4.dsl:4275: SMB2 = Local6
ssdt4.dsl:4286: M459 (" KER-ASL-CpmSmbusExecutor return
0x86\n", Zero)
ssdt4.dsl:4294: SMB0 = 0x1F
ssdt4.dsl:4295: SMB4 = ((Arg3 << One) | Arg1)
ssdt4.dsl:4296: SMB3 = Arg4
ssdt4.dsl:4297: SMB2 = (Arg2 << 0x02)
ssdt4.dsl:4298: Local1 = SMB2 /* \M47A.SMB2 */
ssdt4.dsl:4303: SMB5 = DerefOf (Local7 [One])
ssdt4.dsl:4308: SMB6 = DerefOf (Local7 [0x02])
ssdt4.dsl:4309: SMB5 = DerefOf (Local7 [One])
ssdt4.dsl:4315: SMB5 = Local2
ssdt4.dsl:4319: SMB7 = DerefOf (Local7 [Local1])
ssdt4.dsl:4327: SMB5 = Local2
ssdt4.dsl:4330: SMB2 = ((Arg2 << 0x02) | 0x40)
ssdt4.dsl:4350: Local2 = SMB0 /* \M47A.SMB0 */
ssdt4.dsl:4355: SMB2 = 0x02
ssdt4.dsl:4358: SMB2 = Local6
ssdt4.dsl:4369: M459 (" KER-ASL-CpmSmbusExecutor return
0x87\n", Zero)
ssdt4.dsl:4379: SMB0 = 0x08
ssdt4.dsl:4390: DATB = SMB5 /* \M47A.SMB5 */
ssdt4.dsl:4396: Local0 [0x03] = SMB6 /* \M47A.SMB6 */
ssdt4.dsl:4397: Local0 [0x02] = SMB5 /* \M47A.SMB5 */
ssdt4.dsl:4403: Local2 = SMB2 /* \M47A.SMB2 */
ssdt4.dsl:4404: Local2 = SMB5 /* \M47A.SMB5 */
ssdt4.dsl:4416: Local0 [Local1] = SMB7 /*
\M47A.SMB7 */
ssdt4.dsl:4424: Local1 = (SMB0 & 0x1D)
ssdt4.dsl:4426: SMB0 = 0x1F
ssdt4.dsl:4429: SMB2 = Local6
ssdt4.dsl:4439: M460 (" KER-ASL-CpmSmbusExecutor return St:
0x%X, Len %d, Data: 0x%X, 0x%X, 0x%X, 0x%X ...\n", STAT, LEN, DerefOf
(Local0 [0x02]), DerefOf (Local0 [
ssdt4.dsl:4497: M460 (" KER-ASL-CpmReadSmbusByte (%d, 0x%X,
0x%X) = 0 Smbus Access Disable\n", Arg0, Arg1, Arg2, Zero, Zero, Zero)
ssdt4.dsl:4506: SMB0, 8,
ssdt4.dsl:4507: SMB1, 8,
ssdt4.dsl:4508: SMB2, 8,
ssdt4.dsl:4509: SMB3, 8,
ssdt4.dsl:4510: SMB4, 8,
ssdt4.dsl:4511: SMB5, 8,
ssdt4.dsl:4512: SMB6, 8,
ssdt4.dsl:4513: SMB7, 8,
ssdt4.dsl:4514: SMB8, 8
ssdt4.dsl:4525: Local6 = SMB2 /* \M409.SMB2 */
ssdt4.dsl:4526: SMB2 = (Local6 & 0x7F)
ssdt4.dsl:4533: SMB8 |= 0x10
ssdt4.dsl:4536: Local1 = SMB8 /* \M409.SMB8 */
ssdt4.dsl:4546: SMB0 = 0x1F
ssdt4.dsl:4549: Local1 = SMB0 /* \M409.SMB0 */
ssdt4.dsl:4554: SMB2 = 0x02
ssdt4.dsl:4567: SMB2 = Local6
ssdt4.dsl:4576: M460 (" KER-ASL-CpmReadSmbusByte (%d, 0x%X,
0x%X) = 0 ERROR 1\n", Arg0, Arg1, Arg2, Zero, Zero, Zero)
ssdt4.dsl:4587: SMB1 = 0x3F
ssdt4.dsl:4590: Local1 = SMB1 /* \M409.SMB1 */
ssdt4.dsl:4595: SMB1 = 0x02
ssdt4.dsl:4608: SMB2 = Local6
ssdt4.dsl:4617: M460 (" KER-ASL-CpmReadSmbusByte (%d, 0x%X,
0x%X) = 0 ERROR 2\n", Arg0, Arg1, Arg2, Zero, Zero, Zero)
ssdt4.dsl:4624: SMB0 = 0x1F
ssdt4.dsl:4625: SMB4 = ((Arg1 << One) | One)
ssdt4.dsl:4626: SMB3 = Arg2
ssdt4.dsl:4627: SMB2 = 0x08
ssdt4.dsl:4628: Local1 = SMB2 /* \M409.SMB2 */
ssdt4.dsl:4629: SMB2 = 0x48
ssdt4.dsl:4639: Local1 = SMB0 /* \M409.SMB0 */
ssdt4.dsl:4644: SMB2 = 0x02
ssdt4.dsl:4647: SMB2 = Local6
ssdt4.dsl:4656: M460 (" KER-ASL-CpmReadSmbusByte
(%d, 0x%X, 0x%X) = 0 ERROR 3\n", Arg0, Arg1, Arg2, Zero, Zero, Zero)
ssdt4.dsl:4662: Local1 = SMB0 /* \M409.SMB0 */
ssdt4.dsl:4672: SMB0 = 0x08
ssdt4.dsl:4679: Local4 = SMB5 /* \M409.SMB5 */
ssdt4.dsl:4683: SMB0 = 0x1F
ssdt4.dsl:4684: SMB8 |= 0x20
ssdt4.dsl:4687: SMB2 = Local6
ssdt4.dsl:4696: M460 (" KER-ASL-CpmReadSmbusByte (%d, 0x%X,
0x%X) = 0x%X Success\n", Arg0, Arg1, Arg2, Local4, Zero, Zero)
ssdt4.dsl:4705: M460 (" KER-ASL-CpmWriteSmbusByte (%d, 0x%X,
0x%X, 0x%X) = 0 Smbus Access Disable\n", Arg0, Arg1, Arg2, Arg3, Zero, Zero)
ssdt4.dsl:4714: SMB0, 8,
ssdt4.dsl:4715: SMB1, 8,
ssdt4.dsl:4716: SMB2, 8,
ssdt4.dsl:4717: SMB3, 8,
ssdt4.dsl:4718: SMB4, 8,
ssdt4.dsl:4719: SMB5, 8,
ssdt4.dsl:4720: SMB6, 8,
ssdt4.dsl:4721: SMB7, 8,
ssdt4.dsl:4722: SMB8, 8
ssdt4.dsl:4733: Local6 = SMB2 /* \M410.SMB2 */
ssdt4.dsl:4734: SMB2 = (Local6 & 0x7F)
ssdt4.dsl:4741: SMB8 |= 0x10
ssdt4.dsl:4744: Local1 = SMB8 /* \M410.SMB8 */
ssdt4.dsl:4754: SMB0 = 0x1F
ssdt4.dsl:4757: Local1 = SMB0 /* \M410.SMB0 */
ssdt4.dsl:4762: SMB2 = 0x02
ssdt4.dsl:4775: SMB2 = Local6
ssdt4.dsl:4784: M460 (" KER-ASL-CpmWriteSmbusByte (%d, 0x%X,
0x%X, 0x%X) = 0 ERROR 1\n", Arg0, Arg1, Arg2, Arg3, Zero, Zero)
ssdt4.dsl:4795: SMB1 = 0x3F
ssdt4.dsl:4798: Local1 = SMB1 /* \M410.SMB1 */
ssdt4.dsl:4803: SMB1 = 0x02
ssdt4.dsl:4816: SMB2 = Local6
ssdt4.dsl:4825: M460 (" KER-ASL-CpmWriteSmbusByte (%d, 0x%X,
0x%X, 0x%X) = 0 ERROR 2\n", Arg0, Arg1, Arg2, Arg3, Zero, Zero)
ssdt4.dsl:4832: SMB0 = 0x1F
ssdt4.dsl:4833: SMB4 = (Arg1 << One)
ssdt4.dsl:4834: SMB3 = Arg2
ssdt4.dsl:4835: SMB2 = 0x08
ssdt4.dsl:4836: Local1 = SMB2 /* \M410.SMB2 */
ssdt4.dsl:4837: SMB5 = Arg3
ssdt4.dsl:4838: SMB2 = 0x48
ssdt4.dsl:4848: Local1 = SMB0 /* \M410.SMB0 */
ssdt4.dsl:4853: SMB2 = 0x02
ssdt4.dsl:4856: SMB2 = Local6
ssdt4.dsl:4865: M460 (" KER-ASL-CpmWriteSmbusByte
(%d, 0x%X, 0x%X, 0x%X) = 0 ERROR 3\n", Arg0, Arg1, Arg2, Arg3, Zero, Zero)
ssdt4.dsl:4871: Local1 = SMB0 /* \M410.SMB0 */
ssdt4.dsl:4881: SMB0 = 0x08
ssdt4.dsl:4892: SMB0 = 0x1F
ssdt4.dsl:4893: SMB8 |= 0x20
ssdt4.dsl:4896: SMB2 = Local6
ssdt4.dsl:4905: M460 (" KER-ASL-CpmWriteSmbusByte (%d, 0x%X,
0x%X, 0x%X) Success\n", Arg0, Arg1, Arg2, Arg3, Zero, Zero)
On 9/1/26 10:19 PM, Guenter Roeck wrote:
> Hi Matthew,
>
> On 9/1/26 19:14, Matthew Bettencourt wrote:
>> 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.
>>
>
> It would be something like
>
> sudo acpidump > acpi.log
> acpixtract acpi.log
> iasl -d *.dat
>
> You'll get a number of.dsl files with cryptic assembler-style
> code and data. Then the digging starts ... you may find something
> like "Name (SMB0, 0x0B00)" in dsdt.dsl. Then we can only hope to
> figure out if ACPI actually accesses it.
>
>> 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.
>>
> My pleasure.
>
>> --- 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
>
> Now we'll need to know the port number here (or even better at each step),
> so some duplication of piix4_sb800_port_sel() which only reads the port
> number will be needed.
>
> Note that this may not help at all - whatever entity is modifying the
> registers
> may not change the port number.
>
> Thanks,
> Guenter
>
>> [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: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>>>
>>>>
>>>>
>>>>
>>
>
next prev parent reply other threads:[~2026-09-02 14:00 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-30 23:21 Matthew Bettencourt
2026-08-31 15:12 ` Guenter Roeck
2026-08-31 17:28 ` Guenter Roeck
2026-08-31 23:36 ` Matthew Bettencourt
[not found] ` <37132c40-aa82-4df1-b5ce-337601f3c085@gmail.com>
[not found] ` <3c4e9f59-5272-48cf-a4a0-eeefcba955a9@roeck-us.net>
2026-09-01 0:16 ` Matthew Bettencourt
2026-09-01 3:10 ` Guenter Roeck
2026-09-01 16:31 ` Matthew Bettencourt
2026-09-01 17:04 ` Guenter Roeck
2026-09-01 20:53 ` Matthew Bettencourt
2026-09-01 22:36 ` Guenter Roeck
2026-09-02 0:57 ` Matthew Bettencourt
2026-09-02 1:32 ` Guenter Roeck
2026-09-02 2:14 ` Matthew Bettencourt
2026-09-02 3:19 ` Guenter Roeck
2026-09-02 14:00 ` Matthew Bettencourt [this message]
2026-09-02 14:52 ` Guenter Roeck
2026-09-02 15:26 ` Matthew Bettencourt
2026-09-02 17:21 ` Guenter Roeck
2026-09-02 17:37 ` Matthew Bettencourt
2026-09-02 16:57 ` Armin Wolf
2026-09-02 17:08 ` Matthew Bettencourt
2026-09-02 17:22 ` Armin Wolf
2026-09-02 17:28 ` Matthew Bettencourt
2026-09-02 19:19 ` Armin Wolf
2026-09-02 19:25 ` Matthew Bettencourt
2026-09-02 19:31 ` Armin Wolf
2026-09-02 19:40 ` Matthew Bettencourt
2026-09-02 19:51 ` Armin Wolf
2026-09-03 18:01 ` Matthew Bettencourt
2026-09-03 18:16 ` Guenter Roeck
2026-09-03 18:25 ` Matthew Bettencourt
2026-09-03 21:05 ` Guenter Roeck
2026-09-03 22:47 ` Armin Wolf
2026-09-04 0:24 ` Matthew Bettencourt
2026-09-04 17:58 ` Guenter Roeck
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