Thanks, Sriram, It is better to move this delay out of spin-lock. Best Regards Jerry Huang -----Original Message----- From: Sriram Dash Sent: Thursday, November 24, 2016 7:17 PM To: Jerry Huang <jerry.huang@xxxxxxx>; stern@xxxxxxxxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx Cc: linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; julia.lawall@xxxxxxx; Jerry Huang <jerry.huang@xxxxxxx>; Ramneek Mehresh <ramneek.mehresh@xxxxxxx>; Suresh Gupta <suresh.gupta@xxxxxxx> Subject: RE: [PATCH] fsl/usb: Workarourd for USB erratum-A005697 >From: Changming Huang [mailto:jerry.huang@xxxxxxx] As per USB >specification, in the Suspend state, the status bit does not change >until the port is suspended. However, there may be a delay in >suspending a port if there is a transaction currently in progress on the bus. > >In the USBDR controller, the PORTSCx[SUSP] bit changes immediately when >the application sets it and not when the port is actually suspended > >Workaround for this issue involves waiting for a minimum of 10ms to >allow the controller to go into SUSPEND state before proceeding ahead > >Signed-off-by: Changming Huang <jerry.huang@xxxxxxx> >Signed-off-by: Ramneek Mehresh <ramneek.mehresh@xxxxxxx> >--- > drivers/usb/host/ehci-fsl.c | 3 +++ > drivers/usb/host/ehci-hub.c | 2 ++ > drivers/usb/host/ehci.h | 6 ++++++ > drivers/usb/host/fsl-mph-dr-of.c | 2 ++ > include/linux/fsl_devices.h | 1 + > 5 files changed, 14 insertions(+) > >diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c >index 9f5ffb6..91701cc 100644 >--- a/drivers/usb/host/ehci-fsl.c >+++ b/drivers/usb/host/ehci-fsl.c >@@ -286,6 +286,9 @@ static int ehci_fsl_usb_setup(struct ehci_hcd *ehci) > if (pdata->has_fsl_erratum_a005275 == 1) > ehci->has_fsl_hs_errata = 1; > >+ if (pdata->has_fsl_erratum_a005697 == 1) >+ ehci->has_fsl_susp_errata = 1; >+ > if ((pdata->operating_mode == FSL_USB2_DR_HOST) || > (pdata->operating_mode == FSL_USB2_DR_OTG)) > if (ehci_fsl_setup_phy(hcd, pdata->phy_mode, 0)) diff --git >a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index >74f62d6..86d154e 100644 >--- a/drivers/usb/host/ehci-hub.c >+++ b/drivers/usb/host/ehci-hub.c >@@ -305,6 +305,8 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) > USB_PORT_STAT_HIGH_SPEED) > fs_idle_delay = true; > ehci_writel(ehci, t2, reg); >+ if (ehci_has_fsl_susp_errata(ehci)) >+ mdelay(10); Hi Jerry, Move the delay out of the spin lock. Other than that, it looks fine to me. > changed = 1; > } > } >diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index >3f3b74a..7706e4a 100644 >--- a/drivers/usb/host/ehci.h >+++ b/drivers/usb/host/ehci.h >@@ -219,6 +219,7 @@ struct ehci_hcd { /* one per controller */ > unsigned no_selective_suspend:1; > unsigned has_fsl_port_bug:1; /* FreeScale */ > unsigned has_fsl_hs_errata:1; /* Freescale HS quirk */ >+ unsigned has_fsl_susp_errata:1; /*Freescale SUSP quirk*/ > unsigned big_endian_mmio:1; > unsigned big_endian_desc:1; > unsigned big_endian_capbase:1; >@@ -703,10 +704,15 @@ struct ehci_tt { > #if defined(CONFIG_PPC_85xx) > /* Some Freescale processors have an erratum (USB A-005275) in which > * incoming packets get corrupted in HS mode >+ * Some Freescale processors have an erratum (USB A-005697) in which >+ * we need to wait for 10ms for bus to fo into suspend mode after >+ * setting SUSP bit > */ > #define ehci_has_fsl_hs_errata(e) ((e)->has_fsl_hs_errata) >+#define ehci_has_fsl_susp_errata(e) ((e)->has_fsl_susp_errata) > #else > #define ehci_has_fsl_hs_errata(e) (0) >+#define ehci_has_fsl_susp_errata(e) (0) > #endif > > /* >diff --git a/drivers/usb/host/fsl-mph-dr-of.c >b/drivers/usb/host/fsl-mph-dr-of.c >index f07ccb2..e90ddb5 100644 >--- a/drivers/usb/host/fsl-mph-dr-of.c >+++ b/drivers/usb/host/fsl-mph-dr-of.c >@@ -226,6 +226,8 @@ static int fsl_usb2_mph_dr_of_probe(struct >platform_device *ofdev) > of_property_read_bool(np, "fsl,usb-erratum-a007792"); > pdata->has_fsl_erratum_a005275 = > of_property_read_bool(np, "fsl,usb-erratum-a005275"); >+ pdata->has_fsl_erratum_a005697 = >+ of_property_read_bool(np, "fsl,usb_erratum-a005697"); > > /* > * Determine whether phy_clk_valid needs to be checked diff --git >a/include/linux/fsl_devices.h b/include/linux/fsl_devices.h index >f291291..60cef82 >100644 >--- a/include/linux/fsl_devices.h >+++ b/include/linux/fsl_devices.h >@@ -100,6 +100,7 @@ struct fsl_usb2_platform_data { > unsigned already_suspended:1; > unsigned has_fsl_erratum_a007792:1; > unsigned has_fsl_erratum_a005275:1; >+ unsigned has_fsl_erratum_a005697:1; > unsigned check_phy_clk_valid:1; > > /* register save area for suspend/resume */ >-- >1.7.9.5 Regards, Sriram -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
