From: Alan Stern <stern@rowland.harvard.edu>
To: Yinbo Zhu <yinbo.zhu@nxp.com>
Cc: Xiaobo Xie <xiaobo.xie@nxp.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ramneek Mehresh <ramneek.mehresh@freescale.com>,
Nikhil Badola <nikhil.badola@freescale.com>,
Ran Wang <ran.wang_1@nxp.com>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Jiafei Pan <jiafei.pan@nxp.com>,
Suresh Gupta <B42813@freescale.com>
Subject: Re: [PATCH v5 2/5] usb: phy: Workaround for USB erratum-A005728
Date: Wed, 8 May 2019 10:15:13 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.44L0.1905081013490.1699-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <20190508060608.33882-2-yinbo.zhu@nxp.com>
On Wed, 8 May 2019, Yinbo Zhu wrote:
> From: Suresh Gupta <B42813@freescale.com>
>
> PHY_CLK_VALID bit for UTMI PHY in USBDR does not set even
> if PHY is providing valid clock. Workaround for this
> involves resetting of PHY and check PHY_CLK_VALID bit
> multiple times. If PHY_CLK_VALID bit is still not set even
> after 5 retries, it would be safe to deaclare that PHY
> clock is not available.
> This erratum is applicable for USBDR less then ver 2.4.
>
> Signed-off-by: Suresh Gupta <B42813@freescale.com>
> Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
> ---
> Change in v5:
> remove dev_err function unnecessary parameters
>
> drivers/usb/host/ehci-fsl.c | 37 ++++++++++++++++++++++++++-----------
> drivers/usb/host/ehci-fsl.h | 3 +++
> 2 files changed, 29 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
> index 38674b7..1634ac8 100644
> --- a/drivers/usb/host/ehci-fsl.c
> +++ b/drivers/usb/host/ehci-fsl.c
> @@ -183,6 +183,17 @@ static int fsl_ehci_drv_probe(struct platform_device *pdev)
> return retval;
> }
>
> +static bool usb_phy_clk_valid(struct usb_hcd *hcd)
> +{
> + void __iomem *non_ehci = hcd->regs;
> + bool ret = true;
> +
> + if (!(ioread32be(non_ehci + FSL_SOC_USB_CTRL) & PHY_CLK_VALID))
> + ret = false;
> +
> + return ret;
> +}
> +
> static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
> enum fsl_usb2_phy_modes phy_mode,
> unsigned int port_offset)
> @@ -226,6 +237,16 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
> /* fall through */
> case FSL_USB2_PHY_UTMI:
> case FSL_USB2_PHY_UTMI_DUAL:
> + /* PHY_CLK_VALID bit is de-featured from all controller
> + * versions below 2.4 and is to be checked only for
> + * internal UTMI phy
> + */
> + if (pdata->controller_ver > FSL_USB_VER_2_4 &&
> + pdata->have_sysif_regs && !usb_phy_clk_valid(hcd)) {
> + dev_err(dev, "USB PHY clock invalid\n");
> + return -EINVAL;
> + }
> +
> if (pdata->have_sysif_regs && pdata->controller_ver) {
> /* controller version 1.6 or above */
> tmp = ioread32be(non_ehci + FSL_SOC_USB_CTRL);
> @@ -249,17 +270,11 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
> break;
> }
>
> - /*
> - * check PHY_CLK_VALID to determine phy clock presence before writing
> - * to portsc
> - */
> - if (pdata->check_phy_clk_valid) {
> - if (!(ioread32be(non_ehci + FSL_SOC_USB_CTRL) &
> - PHY_CLK_VALID)) {
> - dev_warn(hcd->self.controller,
> - "USB PHY clock invalid\n");
> - return -EINVAL;
> - }
> + if (pdata->have_sysif_regs &&
> + pdata->controller_ver > FSL_USB_VER_1_6 &&
> + !usb_phy_clk_valid(hcd)) {
This is still wrong. The line above should be indented four characters
less than it is: the '!' should line up with the 'p' in the line above
it.
Alan Stern
> + dev_warn(hcd->self.controller, "USB PHY clock invalid\n");
> + return -EINVAL;
> }
>
> ehci_writel(ehci, portsc, &ehci->regs->port_status[port_offset]);
> diff --git a/drivers/usb/host/ehci-fsl.h b/drivers/usb/host/ehci-fsl.h
> index cbc4220..9d18c6e 100644
> --- a/drivers/usb/host/ehci-fsl.h
> +++ b/drivers/usb/host/ehci-fsl.h
> @@ -50,4 +50,7 @@
> #define UTMI_PHY_EN (1<<9)
> #define ULPI_PHY_CLK_SEL (1<<10)
> #define PHY_CLK_VALID (1<<17)
> +
> +/* Retry count for checking UTMI PHY CLK validity */
> +#define UTMI_PHY_CLK_VALID_CHK_RETRY 5
> #endif /* _EHCI_FSL_H */
>
next prev parent reply other threads:[~2019-05-08 14:15 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-08 6:04 [PATCH v5 1/5] usb: fsl: Set USB_EN bit to select ULPI phy Yinbo Zhu
2019-05-08 6:04 ` [PATCH v5 2/5] usb: phy: Workaround for USB erratum-A005728 Yinbo Zhu
2019-05-08 14:15 ` Alan Stern [this message]
2019-05-09 3:54 ` [EXT] " Yinbo Zhu
2019-05-08 6:04 ` [PATCH v5 3/5] usb: linux/fsl_device: Add platform member has_fsl_erratum_a006918 Yinbo Zhu
2019-05-08 6:04 ` [PATCH v5 4/5] usb: host: Stops USB controller init if PLL fails to lock Yinbo Zhu
2019-05-08 16:50 ` Alan Stern
2019-05-09 3:58 ` [EXT] " Yinbo Zhu
2019-05-08 6:04 ` [PATCH v5 5/5] usb :fsl: Change string format for errata property Yinbo Zhu
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