From e39b2bb3b72b999a04e8d295882be3255aca5ade Mon Sep 17 00:00:00 2001 From: Danesh Petigara Date: Thu, 7 Jan 2016 16:03:33 -0800 Subject: [PATCH] libata: skip debounce delay on link resume The link resume logic uses a 200msec delay while debouncing the SControl register. The rationale behind that delay is to accommodate some PHYs that behave badly if their SStatus/ SControl registers are pounded immediately on resume. The Broadcom STB SATA PHY does not seem to have this issue. This patch introduces a new link flag that allows platforms to skip the debounce delay if it isn't needed. Signed-off-by: Danesh Petigara Signed-off-by: Florian Fainelli Signed-off-by: Tejun Heo --- drivers/ata/ahci_brcmstb.c | 1 + drivers/ata/libata-core.c | 3 ++- include/linux/libata.h | 1 + 3 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/ata/ahci_brcmstb.c b/drivers/ata/ahci_brcmstb.c index f61cbe30786f..b36cae2fd04b 100644 --- a/drivers/ata/ahci_brcmstb.c +++ b/drivers/ata/ahci_brcmstb.c @@ -85,6 +85,7 @@ struct brcm_ahci_priv { static const struct ata_port_info ahci_brcm_port_info = { .flags = AHCI_FLAG_COMMON | ATA_FLAG_NO_DIPM, + .link_flags = ATA_LFLAG_NO_DB_DELAY, .pio_mask = ATA_PIO4, .udma_mask = ATA_UDMA6, .port_ops = &ahci_platform_ops, diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index f5ae6f43b659..cbb74719d2c1 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -3598,7 +3598,8 @@ int sata_link_resume(struct ata_link *link, const unsigned long *params, * immediately after resuming. Delay 200ms before * debouncing. */ - ata_msleep(link->ap, 200); + if (!(link->flags & ATA_LFLAG_NO_DB_DELAY)) + ata_msleep(link->ap, 200); /* is SControl restored correctly? */ if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol))) diff --git a/include/linux/libata.h b/include/linux/libata.h index 83577f8fd15b..088ed924fa66 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -205,6 +205,7 @@ enum { ATA_LFLAG_NO_LPM = (1 << 8), /* disable LPM on this link */ ATA_LFLAG_RST_ONCE = (1 << 9), /* limit recovery to one reset */ ATA_LFLAG_CHANGED = (1 << 10), /* LPM state changed on this link */ + ATA_LFLAG_NO_DB_DELAY = (1 << 11), /* no debounce delay on link resume */ /* struct ata_port flags */ ATA_FLAG_SLAVE_POSS = (1 << 0), /* host supports slave dev */ -- 2.20.1