On Sat, Jan 20, 2024 at 12:51:07AM +0000, Thinh Nguyen wrote: > On Fri, Jan 19, 2024, Frank Li wrote: > > From: Ran Wang <ran.wang_1@xxxxxxx> > > > > When DWC3 is set to host mode by programming register DWC3_GCTL, VBUS > > (or its control signal) will be turned on immediately on related Root Hub > > ports. Then, the VBUS is turned off for a little while(15us) when do xhci > > reset (conducted by xhci driver) and back to normal finally, we can > > observe a negative glitch of related signal happen. > > > > This VBUS glitch might cause some USB devices enumeration fail if kernel > > boot with them connected. Such as LS1012AFWRY/LS1043ARDB/LX2160AQDS > > /LS1088ARDB with Kingston 16GB USB2.0/Kingston USB3.0/JetFlash Transcend > > 4GB USB2.0 drives. The fail cases include enumerated as full-speed device > > or report wrong device descriptor, etc. > > > > One SW workaround which can fix this is by programing all xhci PORTSC[PP] > > to 0 to turn off VBUS immediately after setting host mode in DWC3 driver > > (per signal measurement result, it will be too late to do it in > > xhci-plat.c or xhci.c). Then, after xhci reset complete in xhci driver, > > PORTSC[PP]s' value will back to 1 automatically and VBUS on at that time, > > no glitch happen and normal enumeration process has no impact. > > > > Signed-off-by: Ran Wang <ran.wang_1@xxxxxxx> > > Reviewed-by: Peter Chen <peter.chen@xxxxxxx> > > Signed-off-by: Frank Li <Frank.Li@xxxxxxx> > > --- > > > > Notes: > > Last review at June 06, 2019. Fixed all review comments and sent again. > > > > https://urldefense.com/v3/__https://lore.kernel.org/linux-kernel/AM5PR0402MB2865979E26017BC5937DBBA5F1170@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/__;!!A4F2R9G_pg!bdutJWi1Tcz8SYscB7Mr96SWYMKIo8ElUKgEILFJfK3_60EbECQHXPBmJYAMMhNwQ4YrjxqMZWHdokXhHB6a$ > > > > drivers/usb/dwc3/core.c | 2 ++ > > drivers/usb/dwc3/core.h | 2 ++ > > drivers/usb/dwc3/host.c | 46 +++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 50 insertions(+) > > > > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c > > index 3e55838c00014..a57adf0c11dd1 100644 > > --- a/drivers/usb/dwc3/core.c > > +++ b/drivers/usb/dwc3/core.c > > @@ -1626,6 +1626,8 @@ static void dwc3_get_properties(struct dwc3 *dwc) > > dwc->dis_split_quirk = device_property_read_bool(dev, > > "snps,dis-split-quirk"); > > > > + dwc->host_vbus_glitches = device_property_read_bool(dev, "snps,host-vbus-glitches"); > > This is a quirk. The property should be named with "quirk" subfix. > But do we need a new quirk? How many different platforms are affected? > If it's just 1 or 2, then just use compatible string. more than 2 platform. I think quirk is more flexible. Frank > > > + > > dwc->lpm_nyet_threshold = lpm_nyet_threshold; > > dwc->tx_de_emphasis = tx_de_emphasis; > > > > diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h > > index e3eea965e57bf..0269bacbbf6bd 100644 > > --- a/drivers/usb/dwc3/core.h > > +++ b/drivers/usb/dwc3/core.h > > @@ -1135,6 +1135,7 @@ struct dwc3_scratchpad_array { > > * @dis_split_quirk: set to disable split boundary. > > * @wakeup_configured: set if the device is configured for remote wakeup. > > * @suspended: set to track suspend event due to U3/L2. > > + * @host_vbus_glitches: set to avoid vbus glitch during xhci reset. > > This is only applicable to the first xhci reset in its initialization > and not every xhci reset right? If so, please reword. > > Also, please place it correspond to the order of the field. > > > * @imod_interval: set the interrupt moderation interval in 250ns > > * increments or 0 to disable. > > * @max_cfg_eps: current max number of IN eps used across all USB configs. > > @@ -1353,6 +1354,7 @@ struct dwc3 { > > unsigned tx_de_emphasis:2; > > > > unsigned dis_metastability_quirk:1; > > + unsigned host_vbus_glitches:1; > > > > unsigned dis_split_quirk:1; > > unsigned async_callbacks:1; > > diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c > > index 61f57fe5bb783..af8903ee37c20 100644 > > --- a/drivers/usb/dwc3/host.c > > +++ b/drivers/usb/dwc3/host.c > > @@ -11,6 +11,7 @@ > > #include <linux/of.h> > > #include <linux/platform_device.h> > > > > +#include "../host/xhci.h" > > Let's not import the entire xhci.h. If we're going to share some macros > from xhci.h, please split them from xhci.h and perhaps create > xhci-ports.h for dwc3 to share. > > > #include "core.h" > > > > static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc, > > @@ -28,6 +29,44 @@ static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc, > > dwc->xhci_resources[1].name = name; > > } > > > > +#define XHCI_HCSPARAMS1 0x4 > > +#define XHCI_PORTSC_BASE 0x400 > > + > > +/* > > + * dwc3_power_off_all_roothub_ports - Power off all Root hub ports > > + * @dwc3: Pointer to our controller context structure > > + */ > > +static void dwc3_power_off_all_roothub_ports(struct dwc3 *dwc) > > +{ > > + int i, port_num; > > + u32 reg, op_regs_base, offset; > > + void __iomem *xhci_regs; > > + > > + /* xhci regs is not mapped yet, do it temperary here */ > > + if (dwc->xhci_resources[0].start) { > > + xhci_regs = ioremap(dwc->xhci_resources[0].start, > > + DWC3_XHCI_REGS_END); > > + if (IS_ERR(xhci_regs)) { > > + dev_err(dwc->dev, "Failed to ioremap xhci_regs\n"); > > + return; > > + } > > + > > + op_regs_base = HC_LENGTH(readl(xhci_regs)); > > + reg = readl(xhci_regs + XHCI_HCSPARAMS1); > > + port_num = HCS_MAX_PORTS(reg); > > + > > + for (i = 1; i <= port_num; i++) { > > + offset = op_regs_base + XHCI_PORTSC_BASE + 0x10*(i-1); > > + reg = readl(xhci_regs + offset); > > + reg &= ~PORT_POWER; > > + writel(reg, xhci_regs + offset); > > + } > > + > > + iounmap(xhci_regs); > > + } else > > + dev_err(dwc->dev, "xhci base reg invalid\n"); > > +} > > + > > static int dwc3_host_get_irq(struct dwc3 *dwc) > > { > > struct platform_device *dwc3_pdev = to_platform_device(dwc->dev); > > @@ -66,6 +105,13 @@ int dwc3_host_init(struct dwc3 *dwc) > > int ret, irq; > > int prop_idx = 0; > > > > + /* > > + * We have to power off all Root hub ports immediately after DWC3 set > > + * to host mode to avoid VBUS glitch happen when xhci get reset later. > > + */ > > + if (dwc->host_vbus_glitches) > > + dwc3_power_off_all_roothub_ports(dwc); > > + > > It's part of the dwc3_host_init(), but don't do this in > dwc3_host_get_irq(). Place it where it makes sense. > > > irq = dwc3_host_get_irq(dwc); > > if (irq < 0) > > return irq; > > -- > > 2.34.1 > > > > Please run checkpatch.pl and fix them next time. Regarding > PARENTHESIS_ALIGNMENT or line continuation, it can be two indentations > or parenthesis aligned, whichever one makes it easier to read. > > > From checkpatch: > > CHECK:PARENTHESIS_ALIGNMENT: Alignment should match open parenthesis > #119: FILE: drivers/usb/dwc3/host.c:48: > + xhci_regs = ioremap(dwc->xhci_resources[0].start, > + DWC3_XHCI_REGS_END); > > CHECK:SPACING: spaces preferred around that '*' (ctx:VxV) > #130: FILE: drivers/usb/dwc3/host.c:59: > + offset = op_regs_base + XHCI_PORTSC_BASE + 0x10*(i-1); > ^ > > CHECK:SPACING: spaces preferred around that '-' (ctx:VxV) > #130: FILE: drivers/usb/dwc3/host.c:59: > + offset = op_regs_base + XHCI_PORTSC_BASE + 0x10*(i-1); > ^ > > CHECK:BRACES: Unbalanced braces around else statement > #137: FILE: drivers/usb/dwc3/host.c:66: > + } else > Sorry, I too trust original patch author. Will fix next version Frank > total: 0 errors, 0 warnings, 4 checks, 86 lines checked > > > Thanks, > Thinh
