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xhci: make xhci_handshake timeout for xhci_reset() adjustable
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commit 14073ce upstream.

xhci_reset() timeout was increased from 250ms to 10 seconds in order to
give Renesas 720201 xHC enough time to get ready in probe.

xhci_reset() is called with interrupts disabled in other places, and
waiting for 10 seconds there is not acceptable.

Add a timeout parameter to xhci_reset(), and adjust it back to 250ms
when called from xhci_stop() or xhci_shutdown() where interrupts are
disabled, and successful reset isn't that critical.
This solves issues when deactivating host mode on platforms like SM8450.

For now don't change the timeout if xHC is reset in xhci_resume().
No issues are reported for it, and we need the reset to succeed.
Locking around that reset needs to be revisited later.

Additionally change the signed integer timeout parameter in
xhci_handshake() to a u64 to match the timeout value we pass to
readl_poll_timeout_atomic()

Fixes: 22ceac1 ("xhci: Increase reset timeout for Renesas 720201 host.")
Cc: stable@vger.kernel.org
Reported-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reported-by: Pavan Kondeti <quic_pkondeti@quicinc.com>
Tested-by: Pavan Kondeti <quic_pkondeti@quicinc.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220303110903.1662404-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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matnyman authored and gregkh committed Apr 8, 2022
1 parent 6e3f42c commit 915bce3
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Showing 4 changed files with 16 additions and 15 deletions.
2 changes: 1 addition & 1 deletion drivers/usb/host/xhci-hub.c
Expand Up @@ -762,7 +762,7 @@ static int xhci_exit_test_mode(struct xhci_hcd *xhci)
}
pm_runtime_allow(xhci_to_hcd(xhci)->self.controller);
xhci->test_mode = 0;
return xhci_reset(xhci);
return xhci_reset(xhci, XHCI_RESET_SHORT_USEC);
}

void xhci_set_link_state(struct xhci_hcd *xhci, struct xhci_port *port,
Expand Down
2 changes: 1 addition & 1 deletion drivers/usb/host/xhci-mem.c
Expand Up @@ -2583,7 +2583,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)

fail:
xhci_halt(xhci);
xhci_reset(xhci);
xhci_reset(xhci, XHCI_RESET_SHORT_USEC);
xhci_mem_cleanup(xhci);
return -ENOMEM;
}
20 changes: 9 additions & 11 deletions drivers/usb/host/xhci.c
Expand Up @@ -65,15 +65,15 @@ static bool td_on_ring(struct xhci_td *td, struct xhci_ring *ring)
* handshake done). There are two failure modes: "usec" have passed (major
* hardware flakeout), or the register reads as all-ones (hardware removed).
*/
int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, int usec)
int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, u64 timeout_us)
{
u32 result;
int ret;

ret = readl_poll_timeout_atomic(ptr, result,
(result & mask) == done ||
result == U32_MAX,
1, usec);
1, timeout_us);
if (result == U32_MAX) /* card removed */
return -ENODEV;

Expand Down Expand Up @@ -162,7 +162,7 @@ int xhci_start(struct xhci_hcd *xhci)
* Transactions will be terminated immediately, and operational registers
* will be set to their defaults.
*/
int xhci_reset(struct xhci_hcd *xhci)
int xhci_reset(struct xhci_hcd *xhci, u64 timeout_us)
{
u32 command;
u32 state;
Expand Down Expand Up @@ -195,8 +195,7 @@ int xhci_reset(struct xhci_hcd *xhci)
if (xhci->quirks & XHCI_INTEL_HOST)
udelay(1000);

ret = xhci_handshake(&xhci->op_regs->command,
CMD_RESET, 0, 10 * 1000 * 1000);
ret = xhci_handshake(&xhci->op_regs->command, CMD_RESET, 0, timeout_us);
if (ret)
return ret;

Expand All @@ -209,8 +208,7 @@ int xhci_reset(struct xhci_hcd *xhci)
* xHCI cannot write to any doorbells or operational registers other
* than status until the "Controller Not Ready" flag is cleared.
*/
ret = xhci_handshake(&xhci->op_regs->status,
STS_CNR, 0, 10 * 1000 * 1000);
ret = xhci_handshake(&xhci->op_regs->status, STS_CNR, 0, timeout_us);

xhci->usb2_rhub.bus_state.port_c_suspend = 0;
xhci->usb2_rhub.bus_state.suspended_ports = 0;
Expand Down Expand Up @@ -731,7 +729,7 @@ static void xhci_stop(struct usb_hcd *hcd)
xhci->xhc_state |= XHCI_STATE_HALTED;
xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
xhci_halt(xhci);
xhci_reset(xhci);
xhci_reset(xhci, XHCI_RESET_SHORT_USEC);
spin_unlock_irq(&xhci->lock);

xhci_cleanup_msix(xhci);
Expand Down Expand Up @@ -784,7 +782,7 @@ void xhci_shutdown(struct usb_hcd *hcd)
xhci_halt(xhci);
/* Workaround for spurious wakeups at shutdown with HSW */
if (xhci->quirks & XHCI_SPURIOUS_WAKEUP)
xhci_reset(xhci);
xhci_reset(xhci, XHCI_RESET_SHORT_USEC);
spin_unlock_irq(&xhci->lock);

xhci_cleanup_msix(xhci);
Expand Down Expand Up @@ -1170,7 +1168,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
xhci_dbg(xhci, "Stop HCD\n");
xhci_halt(xhci);
xhci_zero_64b_regs(xhci);
retval = xhci_reset(xhci);
retval = xhci_reset(xhci, XHCI_RESET_LONG_USEC);
spin_unlock_irq(&xhci->lock);
if (retval)
return retval;
Expand Down Expand Up @@ -5316,7 +5314,7 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)

xhci_dbg(xhci, "Resetting HCD\n");
/* Reset the internal HC memory state and registers. */
retval = xhci_reset(xhci);
retval = xhci_reset(xhci, XHCI_RESET_LONG_USEC);
if (retval)
return retval;
xhci_dbg(xhci, "Reset complete\n");
Expand Down
7 changes: 5 additions & 2 deletions drivers/usb/host/xhci.h
Expand Up @@ -229,6 +229,9 @@ struct xhci_op_regs {
#define CMD_ETE (1 << 14)
/* bits 15:31 are reserved (and should be preserved on writes). */

#define XHCI_RESET_LONG_USEC (10 * 1000 * 1000)
#define XHCI_RESET_SHORT_USEC (250 * 1000)

/* IMAN - Interrupt Management Register */
#define IMAN_IE (1 << 1)
#define IMAN_IP (1 << 0)
Expand Down Expand Up @@ -2083,11 +2086,11 @@ void xhci_free_container_ctx(struct xhci_hcd *xhci,

/* xHCI host controller glue */
typedef void (*xhci_get_quirks_t)(struct device *, struct xhci_hcd *);
int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, int usec);
int xhci_handshake(void __iomem *ptr, u32 mask, u32 done, u64 timeout_us);
void xhci_quiesce(struct xhci_hcd *xhci);
int xhci_halt(struct xhci_hcd *xhci);
int xhci_start(struct xhci_hcd *xhci);
int xhci_reset(struct xhci_hcd *xhci);
int xhci_reset(struct xhci_hcd *xhci, u64 timeout_us);
int xhci_run(struct usb_hcd *hcd);
int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks);
void xhci_shutdown(struct usb_hcd *hcd);
Expand Down

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