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usb: host: ehci-platform: add a quirk to avoid stuck

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Since EHCI/OHCI controllers on R-Car Gen3 SoCs are possible to
be getting stuck very rarely after a full/low usb device was
disconnected. To detect/recover from such a situation, the controllers
require a special way which poll the EHCI PORTSC register and changes
the OHCI functional state.

So, this patch adds a polling timer into the ehci-platform driver,
and if the ehci driver detects the issue by the EHCI PORTSC register,
the ehci driver removes a companion device (= the OHCI controller)
to change the OHCI functional state to USB Reset once. And then,
the ehci driver adds the companion device again.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/1580114262-25029-1-git-send-email-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Yoshihiro Shimoda
2020-01-27 17:37:42 +09:00
committed by Greg Kroah-Hartman
parent bb6d3fb354
commit cc7eac1e4a
2 changed files with 128 additions and 1 deletions
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2
include/linux/usb/ehci_def.h
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@@ -151,7 +151,7 @@ struct ehci_regs {
#define PORT_OWNER (1<<13) /* true: companion hc owns this port */
#define PORT_POWER (1<<12) /* true: has power (see PPC) */
#define PORT_USB11(x) (((x)&(3<<10)) == (1<<10)) /* USB 1.1 device */
/* 11:10 for detecting lowspeed devices (reset vs release ownership) */
#define PORT_LS_MASK (3<<10) /* Link status (SE0, K or J */
/* 9 reserved */
#define PORT_LPM (1<<9) /* LPM transaction */
#define PORT_RESET (1<<8) /* reset port */