Re: [PATCH 1/2] ahci: Add Green Sardine vendor ID as board_ahci_mobile
From: Paul Menzel
Date: Tue Feb 15 2022 - 02:06:00 EST
Dear Mario,
Am 14.02.22 um 17:07 schrieb Limonciello, Mario:
+Hans
(For the records, is part of Linux since 5.16-rc2 (commit 1527f69204fe).)
Am 12.11.21 um 21:15 schrieb Mario Limonciello:
AMD requires that the SATA controller be configured for devsleep in order
for S0i3 entry to work properly.
commit b1a9585cc396 ("ata: ahci: Enable DEVSLP by default on x86 with
SLP_S0") sets up a kernel policy to enable devsleep on Intel mobile
platforms that are using s0ix. Add the PCI ID for the SATA controller in
Green Sardine platforms to extend this policy by default for AMD based
systems using s0i3 as well.
Cc: Nehal-bakulchandra Shah <Nehal-bakulchandra.Shah@xxxxxxx>
BugLink:
https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugz
illa.kernel.org%2Fshow_bug.cgi%3Fid%3D214091&data=04%7C01%7Cm
ario.limonciello%40amd.com%7Ca32a202d437544cd2cbb08d9ef9112c0%7C3d
d8961fe4884e608e11a82d994e183d%7C0%7C0%7C637804228648002522%7CU
nknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI
6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=CbfImBnwc8uV1L5QRBuV
PLkP72wpS9yif1UbUwykhNI%3D&reserved=0
You have to love Microsoft Outlook.
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
drivers/ata/ahci.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index d60f34718b5d..1e1167e725a4 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -438,6 +438,7 @@ static const struct pci_device_id ahci_pci_tbl[] = {
/* AMD */
{ PCI_VDEVICE(AMD, 0x7800), board_ahci }, /* AMD Hudson-2 */
{ PCI_VDEVICE(AMD, 0x7900), board_ahci }, /* AMD CZ */
+ { PCI_VDEVICE(AMD, 0x7901), board_ahci_mobile }, /* AMD Green Sardine */
Aren't 0x7900 and 0x7901 the same device only in different modes? I
wonder, why different boards and different comments are used.
No they aren't the same device in different modes.
Reference:
https://www.amd.com/en/support/tech-docs/processor-programming-reference-ppr-for-amd-family-19h-model-51h-revision-a1
Page 33 has a table.
That table misses 0x7900h. (Where can I find it?) coreboot has 0x7900
defined for Cezanne:
src/include/device/pci_ids.h:#define PCI_DEVICE_ID_AMD_CZ_SATA 0x7900
src/soc/amd/stoneyridge/include/soc/pci_devs.h: * SATA_IDE_IDEVID
0x7900
The PCI database too [3]:
FCH SATA Controller [IDE mode]
Additionally, the device 0x7901 is also present in desktop systems like
Dell OptiPlex 5055 and MSI B350 MORTAR. Is `board_ahci_mobile` the right
board then? Or should the flag `AHCI_HFLAG_IS_MOBILE` be renamed to
avoid confusion?
Are you having a problem or just want clarity in the enum definition?
It’s more about clarity, and understanding the two different entries.
This was introduced by Hans in commit ebb82e3c79d2a to set LPM policy properly
for a number of mobile devices.
My opinion here is that the policy being for "mobile" devices only is short sighted as power
consumption policy on desktops is also relevant as OEMs ship desktops that need to meet
various power regulations for those too.
So I would be in the camp for renaming the flags.
Why can’t the LPM policy, if available(?), not be set for `board_ahci`
by default, so `board_ahci_mobile` could be removed?
/* AMD is using RAID class only for ahci controllers */
{ PCI_VENDOR_ID_AMD, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
PCI_CLASS_STORAGE_RAID << 8, 0xffffff, board_ahci },
Kind regards,
Paul
[1]: https://review.coreboot.org/10418
[2]: https://review.coreboot.org/20200
[3]: https://pci-ids.ucw.cz/read/PC/1022/7900