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authorEugene Korenevsky <ekorenevsky@astralinux.ru>2021-01-10 20:36:09 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-01-12 19:16:37 +0300
commit280a9045bb18833db921b316a5527d2b565e9f2e (patch)
tree3ba47c9fdf46093bd5ebde9908ed57acfa86ef06 /drivers/usb/host
parent5f8e084026543bc06eb9b2a623de55bb4ab3e60e (diff)
downloadlinux-280a9045bb18833db921b316a5527d2b565e9f2e.tar.xz
ehci: fix EHCI host controller initialization sequence
According to EHCI spec, EHCI HC clears USBSTS.HCHalted whenever USBCMD.RS=1. However, it is a good practice to wait some time after setting USBCMD.RS (approximately 100ms) until USBSTS.HCHalted become zero. Without this waiting, VirtualBox's EHCI virtual HC accidentally hangs (see BugLink). BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=211095 Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Eugene Korenevsky <ekorenevsky@astralinux.ru> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210110173609.GA17313@himera.home Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host')
-rw-r--r--drivers/usb/host/ehci-hcd.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index e358ae17d51e..1926b328b6aa 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -574,6 +574,7 @@ static int ehci_run (struct usb_hcd *hcd)
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
u32 temp;
u32 hcc_params;
+ int rc;
hcd->uses_new_polling = 1;
@@ -629,9 +630,20 @@ static int ehci_run (struct usb_hcd *hcd)
down_write(&ehci_cf_port_reset_rwsem);
ehci->rh_state = EHCI_RH_RUNNING;
ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag);
+
+ /* Wait until HC become operational */
ehci_readl(ehci, &ehci->regs->command); /* unblock posted writes */
msleep(5);
+ rc = ehci_handshake(ehci, &ehci->regs->status, STS_HALT, 0, 100 * 1000);
+
up_write(&ehci_cf_port_reset_rwsem);
+
+ if (rc) {
+ ehci_err(ehci, "USB %x.%x, controller refused to start: %d\n",
+ ((ehci->sbrn & 0xf0)>>4), (ehci->sbrn & 0x0f), rc);
+ return rc;
+ }
+
ehci->last_periodic_enable = ktime_get_real();
temp = HC_VERSION(ehci, ehci_readl(ehci, &ehci->caps->hc_capbase));