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usb: dwc3: Add workaround for host mode VBUS glitch when boot

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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.

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20240124152525.3910311-4-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ran Wang 2024-01-24 10:25:25 -05:00 committed by Greg Kroah-Hartman
parent bc83a87759
commit 2d2a334952
3 changed files with 56 additions and 0 deletions
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3
drivers/usb/dwc3/core.c
View File

@ -1626,6 +1626,9 @@ 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_quirk = device_property_read_bool(dev,
"snps,host-vbus-glitches-quirk");
dwc->lpm_nyet_threshold = lpm_nyet_threshold;
dwc->tx_de_emphasis = tx_de_emphasis;

2
drivers/usb/dwc3/core.h
View File

@ -1132,6 +1132,7 @@ struct dwc3_scratchpad_array {
* 2 - No de-emphasis
* 3 - Reserved
* @dis_metastability_quirk: set to disable metastability quirk.
* @host_vbus_glitches_quirk: set to avoid vbus glitch during xhci reset.
* @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.
@ -1353,6 +1354,7 @@ struct dwc3 {
unsigned tx_de_emphasis:2;
unsigned dis_metastability_quirk:1;
unsigned host_vbus_glitches_quirk:1;
unsigned dis_split_quirk:1;
unsigned async_callbacks:1;

51
drivers/usb/dwc3/host.c
View File

@ -11,8 +11,52 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include "../host/xhci-port.h"
#include "../host/xhci-ext-caps.h"
#include "../host/xhci-caps.h"
#include "core.h"
#define XHCI_HCSPARAMS1 0x4
#define XHCI_PORTSC_BASE 0x400
/**
* dwc3_power_off_all_roothub_ports - Power off all Root hub ports
* @dwc: Pointer to our controller context structure
*/
static void dwc3_power_off_all_roothub_ports(struct dwc3 *dwc)
{
void __iomem *xhci_regs;
u32 op_regs_base;
int port_num;
u32 offset;
u32 reg;
int i;
/* 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 void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
int irq, char *name)
{
@ -66,6 +110,13 @@ int dwc3_host_init(struct dwc3 *dwc)
int ret, irq;
int prop_idx = 0;
/*
* Some platforms need 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_quirk)
dwc3_power_off_all_roothub_ports(dwc);
irq = dwc3_host_get_irq(dwc);
if (irq < 0)
return irq;