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| author | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2015-09-26 23:32:08 +0200 |
|---|---|---|
| committer | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2015-09-26 23:32:08 +0200 |
| commit | 995e5cb4b2e6b96af4b63c8ebc3f4f6c6e5c8d0d (patch) | |
| tree | bfbcfdd422158ed6bca1d77f5450e0626e31eb0a /arch/arm | |
| parent | 6728b56768d42f741c7139ff78d5e1cb6e22da7b (diff) | |
apalis/colibri_t30: usb: fix performance regression
Unfortunately that utmi_phy_remotewake_detected() function gets called
one too many times even quite continuously during data transfers and
putting an mdelay() in there has a rather adverse effect on the overall
system performance including of course degrading USB transfer speeds.
Moving the system lock-up avoidance hack further down into the if
clause improves the performance again as this typically is only ever
evaluated once upon actually plugging something in behind a hub.
This fixes a performance regression introduced by the following commit:
apalis/colibri_t30: usb: fix low-speed issue hack
629b91fa046df5213ed3312d2e2b8683e6bdd70c
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/mach-tegra/tegra3_usb_phy.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm/mach-tegra/tegra3_usb_phy.c b/arch/arm/mach-tegra/tegra3_usb_phy.c index 0ab61758addd..f1a1e0874946 100644 --- a/arch/arm/mach-tegra/tegra3_usb_phy.c +++ b/arch/arm/mach-tegra/tegra3_usb_phy.c @@ -755,12 +755,15 @@ bool utmi_phy_remotewake_detected(struct tegra_usb_phy *phy) unsigned int inst = phy->inst; u32 val; - /* Hack: avoid system lock-up condition upon device hot-plugging */ - mdelay(4); - DBG("%s(%d) inst:[%d]\n", __func__, __LINE__, phy->inst); val = readl(base + UTMIP_PMC_WAKEUP0); if (val & EVENT_INT_ENB) { + /* + * Hack: avoid system lock-up condition upon device hot-plugging + * behind a hub + */ + mdelay(4); + val = readl(pmc_base + UTMIP_UHSIC_STATUS); if (UTMIP_WAKE_ALARM(inst) & val) { val = readl(pmc_base + PMC_SLEEP_CFG); |