| From b030b133db9a77419122df4b7db74b65377321e3 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 3 Jun 2021 17:59:21 +0200 |
| Subject: usb: dwc2: Don't reset the core after setting turnaround time |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Clément Lassieur <clement@lassieur.org> |
| |
| [ Upstream commit aafe93516b8567ab5864e1f4cd3eeabc54fb0e5a ] |
| |
| Every time the hub signals a reset while we (device) are hsotg->connected, |
| dwc2_hsotg_core_init_disconnected() is called, which in turn calls |
| dwc2_hs_phy_init(). |
| |
| GUSBCFG.USBTrdTim is cleared upon Core Soft Reset, so if |
| hsotg->params.phy_utmi_width is 8-bit, the value of GUSBCFG.USBTrdTim (the |
| default one: 0x5, corresponding to 16-bit) is always different from |
| hsotg->params.phy_utmi_width, thus dwc2_core_reset() is called every |
| time (usbcfg != usbcfg_old), which causes 2 issues: |
| |
| 1) The call to dwc2_core_reset() does another reset 300us after the initial |
| Chirp K of the first reset (which should last at least Tuch = 1ms), and |
| messes up the High-speed Detection Handshake: both hub and device drive |
| current into the D+ and D- lines at the same time. |
| |
| 2) GUSBCFG.USBTrdTim is cleared by the second reset, so its value is always |
| the default one (0x5). |
| |
| Setting GUSBCFG.USBTrdTim after the potential call to dwc2_core_reset() |
| fixes both issues. It is now set even when select_phy is false because the |
| cost of the Core Soft Reset is removed. |
| |
| Fixes: 1e868545f2bb ("usb: dwc2: gadget: Move gadget phy init into core phy init") |
| Signed-off-by: Clément Lassieur <clement@lassieur.org> |
| Link: https://lore.kernel.org/r/20210603155921.940651-1-clement@lassieur.org |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/usb/dwc2/core.c | 30 +++++++++++++++++++++--------- |
| 1 file changed, 21 insertions(+), 9 deletions(-) |
| |
| diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c |
| index fec17a2d2447..15911ac7582b 100644 |
| --- a/drivers/usb/dwc2/core.c |
| +++ b/drivers/usb/dwc2/core.c |
| @@ -1167,15 +1167,6 @@ static int dwc2_hs_phy_init(struct dwc2_hsotg *hsotg, bool select_phy) |
| usbcfg &= ~(GUSBCFG_ULPI_UTMI_SEL | GUSBCFG_PHYIF16); |
| if (hsotg->params.phy_utmi_width == 16) |
| usbcfg |= GUSBCFG_PHYIF16; |
| - |
| - /* Set turnaround time */ |
| - if (dwc2_is_device_mode(hsotg)) { |
| - usbcfg &= ~GUSBCFG_USBTRDTIM_MASK; |
| - if (hsotg->params.phy_utmi_width == 16) |
| - usbcfg |= 5 << GUSBCFG_USBTRDTIM_SHIFT; |
| - else |
| - usbcfg |= 9 << GUSBCFG_USBTRDTIM_SHIFT; |
| - } |
| break; |
| default: |
| dev_err(hsotg->dev, "FS PHY selected at HS!\n"); |
| @@ -1197,6 +1188,24 @@ static int dwc2_hs_phy_init(struct dwc2_hsotg *hsotg, bool select_phy) |
| return retval; |
| } |
| |
| +static void dwc2_set_turnaround_time(struct dwc2_hsotg *hsotg) |
| +{ |
| + u32 usbcfg; |
| + |
| + if (hsotg->params.phy_type != DWC2_PHY_TYPE_PARAM_UTMI) |
| + return; |
| + |
| + usbcfg = dwc2_readl(hsotg, GUSBCFG); |
| + |
| + usbcfg &= ~GUSBCFG_USBTRDTIM_MASK; |
| + if (hsotg->params.phy_utmi_width == 16) |
| + usbcfg |= 5 << GUSBCFG_USBTRDTIM_SHIFT; |
| + else |
| + usbcfg |= 9 << GUSBCFG_USBTRDTIM_SHIFT; |
| + |
| + dwc2_writel(hsotg, usbcfg, GUSBCFG); |
| +} |
| + |
| int dwc2_phy_init(struct dwc2_hsotg *hsotg, bool select_phy) |
| { |
| u32 usbcfg; |
| @@ -1214,6 +1223,9 @@ int dwc2_phy_init(struct dwc2_hsotg *hsotg, bool select_phy) |
| retval = dwc2_hs_phy_init(hsotg, select_phy); |
| if (retval) |
| return retval; |
| + |
| + if (dwc2_is_device_mode(hsotg)) |
| + dwc2_set_turnaround_time(hsotg); |
| } |
| |
| if (hsotg->hw_params.hs_phy_type == GHWCFG2_HS_PHY_TYPE_ULPI && |
| -- |
| 2.30.2 |
| |