On 12/30/21 01:11, Paul Menzel wrote: > Since the first commit 1da177e4c3 (Linux-2.6.12-rc2) in the Linux git > repository, `sata_link_resume()` contains a 200 ms delay with the comment > below. > >> /* >> * Some PHYs react badly if SStatus is pounded >> * immediately after resuming. Delay 200ms before >> * debouncing. >> */ This is code comment so no need to "quote" this in the commit message (line starting with '>'). Seeing the patch in an email client, it looks weird :) > > A lot of PHYs do not have that problem though, so delaying 200 ms increases > the boot time by 30 percent unnecessarily for a lot of systems, making > “instant booting” quite hard. > > As it’s unknown for what PHY the delay was added, create a new board > `board_ahci_nodbdelay` with the link flag `ATA_LFLAG_NO_DB_DELAY,`, and, > for now, configure the AMD A85 FCH (Hudson D4) to use it. > > On the ASUS F2A85-M PRO it reduces the Linux kernel boot time by the > expected 200 ms from 787 ms to 585 ms. > > Tested on ASUS F2A85-M PRO: > > Without patch, i. e., with 200 ms debounce delay: > > […] > [ 0.000000] DMI: ASUS F2A85-M_PRO/F2A85-M_PRO, BIOS 4.15-671-g7b043ef855 12/27/2021 > […] > [ 0.404885] ahci 0000:00:11.0: version 3.0 > [ 0.405466] ahci 0000:00:11.0: AHCI 0001.0300 32 slots 8 ports 6 Gbps 0x40 impl SATA mode > [ 0.405470] ahci 0000:00:11.0: flags: 64bit ncq sntf ilck led clo pio > [ 0.408036] scsi host0: ahci > [ 0.408537] scsi host1: ahci > [ 0.408932] scsi host2: ahci > [ 0.409444] scsi host3: ahci > [ 0.409841] scsi host4: ahci > [ 0.410266] scsi host5: ahci > [ 0.410661] scsi host6: ahci > [ 0.411052] scsi host7: ahci > [ 0.411284] ata1: DUMMY > [ 0.411286] ata2: DUMMY > [ 0.411286] ata3: DUMMY > [ 0.411287] ata4: DUMMY > [ 0.411288] ata5: DUMMY > [ 0.411289] ata6: DUMMY > [ 0.411291] ata7: SATA max UDMA/133 abar m2048@0xf01cc000 port 0xf01cc400 irq 19 > [ 0.411292] ata8: DUMMY > […] > [ 0.422362] Key type encrypted registered > [ 0.424903] PM: Magic number: 1:28:636 > [ 0.723979] ata7: SATA link up 6.0 Gbps (SStatus 133 SControl 300) > [ 0.724268] ata7.00: ATA-9: SanDisk SDSSDP064G, 2.0.0, max UDMA/133 > [ 0.724271] ata7.00: 125045424 sectors, multi 1: LBA48 NCQ (depth 32) > [ 0.725537] ata7.00: configured for UDMA/133 > [ 0.725898] scsi 6:0:0:0: Direct-Access ATA SanDisk SDSSDP06 0 PQ: 0 ANSI: 5 > [ 0.726428] sd 6:0:0:0: [sda] 125045424 512-byte logical blocks: (64.0 GB/59.6 GiB) > [ 0.726442] sd 6:0:0:0: [sda] Write Protect is off > [ 0.726446] sd 6:0:0:0: [sda] Mode Sense: 00 3a 00 00 > [ 0.726464] sd 6:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA > [ 0.727985] sda: sda1 sda2 sda3 > [ 0.728588] sd 6:0:0:0: [sda] Attached SCSI disk > [ 0.738495] EXT4-fs (sda3): mounted filesystem with ordered data mode. Opts: (null). Quota mode: none. > […] > [ 0.786812] Run /sbin/init as init process > > With patch, i. e., skipping the debounce delay saves 200 ms from the boot > as expected. > > […] > [ 0.000000] DMI: ASUS F2A85-M_PRO/F2A85-M_PRO, BIOS 4.15-671-g7b043ef855 12/27/2021 > […] > [ 0.407372] ahci 0000:00:11.0: version 3.0 > [ 0.407909] ahci 0000:00:11.0: AHCI 0001.0300 32 slots 8 ports 6 Gbps 0x40 impl SATA mode > [ 0.407913] ahci 0000:00:11.0: flags: 64bit ncq sntf ilck led clo pio > [ 0.410520] scsi host0: ahci > [ 0.411017] scsi host1: ahci > [ 0.411418] scsi host2: ahci > [ 0.411810] scsi host3: ahci > [ 0.412225] scsi host4: ahci > [ 0.412614] scsi host5: ahci > [ 0.413005] scsi host6: ahci > [ 0.413488] scsi host7: ahci > [ 0.413713] ata1: DUMMY > [ 0.413715] ata2: DUMMY > [ 0.413716] ata3: DUMMY > [ 0.413716] ata4: DUMMY > [ 0.413717] ata5: DUMMY > [ 0.413718] ata6: DUMMY > [ 0.413720] ata7: SATA max UDMA/133 abar m2048@0xf01cc000 port 0xf01cc400 irq 19 > [ 0.413722] ata8: DUMMY > […] > [ 0.425414] Key type encrypted registered > [ 0.427873] PM: Magic number: 1:234:838 > [ 0.522131] ata7: SATA link up 6.0 Gbps (SStatus 133 SControl 300) > [ 0.522415] ata7.00: ATA-9: SanDisk SDSSDP064G, 2.0.0, max UDMA/133 > [ 0.522418] ata7.00: 125045424 sectors, multi 1: LBA48 NCQ (depth 32) > [ 0.523636] ata7.00: configured for UDMA/133 > [ 0.523993] scsi 6:0:0:0: Direct-Access ATA SanDisk SDSSDP06 0 PQ: 0 ANSI: 5 > [ 0.524497] sd 6:0:0:0: [sda] 125045424 512-byte logical blocks: (64.0 GB/59.6 GiB) > [ 0.524511] sd 6:0:0:0: [sda] Write Protect is off > [ 0.524515] sd 6:0:0:0: [sda] Mode Sense: 00 3a 00 00 > [ 0.524534] sd 6:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA > [ 0.525953] sda: sda1 sda2 sda3 > [ 0.526541] sd 6:0:0:0: [sda] Attached SCSI disk > [ 0.536245] EXT4-fs (sda3): mounted filesystem with ordered data mode. Opts: (null). Quota mode: none. > […] > [ 0.585327] Run /sbin/init as init process > > Signed-off-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx> > Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> > Cc: Guenter Roeck <groeck@xxxxxxxxxxxx> > > --- > > Add the two Chromium OS developers Dmitry and Guenter to Cc, as to my > knowledge Chromium/Chrome OS also tries to boot very fast, and the Chromium > project has some CI infrastructure. > --- > drivers/ata/ahci.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c > index 6a2432e4adda..4f3e0603864d 100644 > --- a/drivers/ata/ahci.c > +++ b/drivers/ata/ahci.c > @@ -51,6 +51,7 @@ enum board_ids { > board_ahci, > board_ahci_ign_iferr, > board_ahci_mobile, > + board_ahci_nodbdelay, The "nodb" naming is not super clear... Maybe change the name to: board_ahci_no_debounce_delay or board_ahci_no_resume_delay ? Longer, but clearer. > board_ahci_nomsi, > board_ahci_noncq, > board_ahci_nosntf, > @@ -141,6 +142,13 @@ static const struct ata_port_info ahci_port_info[] = { > .udma_mask = ATA_UDMA6, > .port_ops = &ahci_ops, > }, > + [board_ahci_nodbdelay] = { > + .flags = AHCI_FLAG_COMMON, > + .link_flags = ATA_LFLAG_NO_DB_DELAY, > + .pio_mask = ATA_PIO4, > + .udma_mask = ATA_UDMA6, > + .port_ops = &ahci_ops, > + }, > [board_ahci_nomsi] = { > AHCI_HFLAGS (AHCI_HFLAG_NO_MSI), > .flags = AHCI_FLAG_COMMON, > @@ -437,6 +445,7 @@ static const struct pci_device_id ahci_pci_tbl[] = { > board_ahci_al }, > /* AMD */ > { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_HUDSON2_SATA_IDE), board_ahci }, > + { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_HUDSON2_SATA_AHCI), board_ahci_nodbdelay }, Patch 1 introduces this macro in pci_ids.h, but it is used only here. So to keep with the current style in this structure, drop the macro (so drop patch 1). > { PCI_VDEVICE(AMD, 0x7900), board_ahci }, /* AMD CZ */ > { PCI_VDEVICE(AMD, 0x7901), board_ahci_mobile }, /* AMD Green Sardine */ > /* AMD is using RAID class only for ahci controllers */ -- Damien Le Moal Western Digital Research