| Message ID | 20240426220748.28184-2-pmenzel@molgen.mpg.de |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] i2c: smbus: Add (LP)DDR5 types to `i2c_register_spd()` | expand |
Hi Paul,
> 1. I have no idea if the name ee1004 is correct.
I am afraid this won't work. It was tried already in 2023:
https://www.spinics.net/lists/linux-i2c/msg62267.html
Especially note Jean's answer here:
https://www.spinics.net/lists/linux-i2c/msg62420.html
So, DDR5 probably needs a new driver.
But thanks for trying!
Wolfram
Dear Wolfram, Am 27.04.24 um 11:14 schrieb Wolfram Sang: >> 1. I have no idea if the name ee1004 is correct. > > I am afraid this won't work. It was tried already in 2023: > > https://www.spinics.net/lists/linux-i2c/msg62267.html > > Especially note Jean's answer here: > > https://www.spinics.net/lists/linux-i2c/msg62420.html > > So, DDR5 probably needs a new driver. > > But thanks for trying! Thank you for digging this up. Would it be alright, to adapt the warning for (LP)DDR5? Kind regards, Paul
> Thank you for digging this up. Would it be alright, to adapt the warning for > (LP)DDR5? Sure, good idea. I think it will be helpful to include the standard name in the message, so people have a starting point, like: "DDR5 SPD not supported. JEDEC JESD300-5 compatible driver does not exist yet" Or similar...
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c index 97f338b123b1..0d67a95c0599 100644 --- a/drivers/i2c/i2c-smbus.c +++ b/drivers/i2c/i2c-smbus.c @@ -308,7 +308,7 @@ EXPORT_SYMBOL_GPL(i2c_free_slave_host_notify_device); * target systems are the same. * Restrictions to automatic SPD instantiation: * - Only works if all filled slots have the same memory type - * - Only works for DDR, DDR2, DDR3 and DDR4 for now + * - Only works for DDR, DDR2, DDR3, DDR4 and DDR5 for now * - Only works on systems with 1 to 8 memory slots */ #if IS_ENABLED(CONFIG_DMI) @@ -380,6 +380,8 @@ void i2c_register_spd(struct i2c_adapter *adap) break; case 0x1A: /* DDR4 */ case 0x1E: /* LPDDR4 */ + case 0x22: /* DDR5 */ + case 0x23: /* LPDDR5 */ name = "ee1004"; break; default:
On several systems Linux logs: i2c i2c-0: Memory type 0x22 not supported yet, not instantiating SPD 1. Supermicro Super Server/X13SAE, BIOS 2.0 10/17/2022 2. Dell Inc. Precision 3660/0PRR48, BIOS 2.9.3 11/22/2023 3. Dell Inc. OptiPlex SFF Plus 7010/0YGWFV, BIOS 1.7.1 08/11/2023 4. Run `git grep 'emory type.*supported yet, not instantiating SPD'` in the repository of dmesg reports for various computers collected by Linux users at https://linux-hardware.org. [1] Add 0x22 and 0x23 for DDR5 according to section 7.18.2 (Memory Device — Type), table 78 in *System Management BIOS (SMBIOS) Reference Specification*, version 3.6.0 [2]. The same name *ee1004* as for DDR4 is used. Successfully tested on Supermicro Super Server/X13SAE, BIOS 2.0 10/17/2022: [ 5.459383] i801_smbus 0000:00:1f.4: SPD Write Disable is set [ 5.465180] i801_smbus 0000:00:1f.4: SMBus using PCI interrupt [ 5.465803] intel_pstate: HWP enabled by BIOS [ 5.474046] i2c i2c-0: Successfully instantiated SPD at 0x50 [ 5.475379] intel_pstate: Intel P-state driver initializing [ 5.487129] i2c i2c-0: Successfully instantiated SPD at 0x51 [ 5.487350] intel_pstate: HWP enabled [ 5.493288] i2c i2c-0: Successfully instantiated SPD at 0x52 [ 5.496481] hid: raw HID events driver (C) Jiri Kosina [ 5.502695] i2c i2c-0: Successfully instantiated SPD at 0x53 [1]: https://github.com/linuxhw/Dmesg [2]: https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.6.0.pdf Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de> Cc: Jean Delvare <jdelvare@suse.de> --- 1. I have no idea if the name ee1004 is correct. 2. Should I test other things besides looking at the Linux messages? drivers/i2c/i2c-smbus.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)