| Message ID | 20230808102959.479264-1-xu.yang_2@nxp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/2] usb: ehci: add workaround for chipidea PORTSC.PEC bug | expand |
On Tue, Aug 08, 2023 at 06:29:58PM +0800, Xu Yang wrote: > Some NXP processor using chipidea IP has a bug when frame babble is > detected. > > As per 4.15.1.1.1 Serial Bus Babble: > A babble condition also exists if IN transaction is in progress at > High-speed SOF2 point. This is called frame balle. The host controller s/balle/babble/ > must disable the port to which the frame babble is detected. > > The USB controller has disabled the port (PE cleared) and has asserted > USBERRINT when frame babble is detected, but PEC is not asserted. > Therefore, the SW didn't aware that port has been disabled. Then the s/didn't/isn't/ > SW keeps sending packets to this port, but all of the transfers will > fail. > > This workaround will firstly assert PCD by SW when USBERRINT is detected > and then judge whether port change has really occurred or not by polling > roothub status. Because the PEC doesn't get asserted in our case, this > patch will also assert it by SW when specific conditions are satisfied. > > Signed-off-by: Xu Yang <xu.yang_2@nxp.com> > --- > drivers/usb/host/ehci-hcd.c | 5 +++++ > drivers/usb/host/ehci-hub.c | 10 +++++++++- > drivers/usb/host/ehci.h | 10 ++++++++++ > 3 files changed, 24 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c > index a1930db0da1c..d6b276c354db 100644 > --- a/drivers/usb/host/ehci-hcd.c > +++ b/drivers/usb/host/ehci-hcd.c > @@ -762,6 +762,11 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd) > bh = 1; > } > > + /* Force to check port status */ > + if (ehci->has_ci_pec_bug && (status & STS_ERR) > + && !(status & STS_PCD)) > + status |= STS_PCD; Suggestion for minor improvement: First, you don't really need the (status & STS_PCD) test, because if the bit is already set then turning it again on won't matter. Second, after that test has been removed you can merge this code with the INCR(ehci->stats.error) line above, removing the (status & STS_ERR) test. The rest of the patch looks okay. Alan Stern
Hi Alan, > On Tue, Aug 08, 2023 at 06:29:58PM +0800, Xu Yang wrote: > > Some NXP processor using chipidea IP has a bug when frame babble is > > detected. > > > > As per 4.15.1.1.1 Serial Bus Babble: > > A babble condition also exists if IN transaction is in progress at > > High-speed SOF2 point. This is called frame balle. The host controller > > s/balle/babble/ Okay. > > > must disable the port to which the frame babble is detected. > > > > The USB controller has disabled the port (PE cleared) and has asserted > > USBERRINT when frame babble is detected, but PEC is not asserted. > > Therefore, the SW didn't aware that port has been disabled. Then the > > s/didn't/isn't/ Okay. > > > SW keeps sending packets to this port, but all of the transfers will > > fail. > > > > This workaround will firstly assert PCD by SW when USBERRINT is detected > > and then judge whether port change has really occurred or not by polling > > roothub status. Because the PEC doesn't get asserted in our case, this > > patch will also assert it by SW when specific conditions are satisfied. > > > > Signed-off-by: Xu Yang <xu.yang_2@nxp.com> > > --- > > drivers/usb/host/ehci-hcd.c | 5 +++++ > > drivers/usb/host/ehci-hub.c | 10 +++++++++- > > drivers/usb/host/ehci.h | 10 ++++++++++ > > 3 files changed, 24 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c > > index a1930db0da1c..d6b276c354db 100644 > > --- a/drivers/usb/host/ehci-hcd.c > > +++ b/drivers/usb/host/ehci-hcd.c > > @@ -762,6 +762,11 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd) > > bh = 1; > > } > > > > + /* Force to check port status */ > > + if (ehci->has_ci_pec_bug && (status & STS_ERR) > > + && !(status & STS_PCD)) > > + status |= STS_PCD; > > Suggestion for minor improvement: First, you don't really need the > (status & STS_PCD) test, because if the bit is already set then turning > it again on won't matter. Second, after that test has been removed you > can merge this code with the INCR(ehci->stats.error) line above, > removing the (status & STS_ERR) test. Okay. Will try this. Thanks, Xu Yang > > The rest of the patch looks okay. > > Alan Stern
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index a1930db0da1c..d6b276c354db 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -762,6 +762,11 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd) bh = 1; } + /* Force to check port status */ + if (ehci->has_ci_pec_bug && (status & STS_ERR) + && !(status & STS_PCD)) + status |= STS_PCD; + /* complete the unlinking of some qh [4.15.2.3] */ if (status & STS_IAA) { diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index efe30e3be22f..1aee392e8492 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -674,7 +674,8 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf) if ((temp & mask) != 0 || test_bit(i, &ehci->port_c_suspend) || (ehci->reset_done[i] && time_after_eq( - jiffies, ehci->reset_done[i]))) { + jiffies, ehci->reset_done[i])) + || ehci_has_ci_pec_bug(ehci, temp)) { if (i < 7) buf [0] |= 1 << (i + 1); else @@ -875,6 +876,13 @@ int ehci_hub_control( if (temp & PORT_PEC) status |= USB_PORT_STAT_C_ENABLE << 16; + if (ehci_has_ci_pec_bug(ehci, temp)) { + status |= USB_PORT_STAT_C_ENABLE << 16; + ehci_info(ehci, + "PE is cleared by HW port:%d PORTSC:%08x\n", + wIndex + 1, temp); + } + if ((temp & PORT_OCC) && (!ignore_oc && !ehci->spurious_oc)){ status |= USB_PORT_STAT_C_OVERCURRENT << 16; diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index c5c7f8782549..1441e3400796 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -207,6 +207,7 @@ struct ehci_hcd { /* one per controller */ unsigned has_fsl_port_bug:1; /* FreeScale */ unsigned has_fsl_hs_errata:1; /* Freescale HS quirk */ unsigned has_fsl_susp_errata:1; /* NXP SUSP quirk */ + unsigned has_ci_pec_bug:1; /* ChipIdea PEC bug */ unsigned big_endian_mmio:1; unsigned big_endian_desc:1; unsigned big_endian_capbase:1; @@ -707,6 +708,15 @@ ehci_port_speed(struct ehci_hcd *ehci, unsigned int portsc) */ #define ehci_has_fsl_susp_errata(e) ((e)->has_fsl_susp_errata) +/* + * Some Freescale/NXP processors using ChipIdea IP have a bug in which + * disabling the port (PE is cleared) does not cause PEC to be asserted + * when frame babble is detected. + */ +#define ehci_has_ci_pec_bug(e, portsc) \ + ((e)->has_ci_pec_bug && ((e)->command & CMD_PSE) \ + && !(portsc & PORT_PEC) && !(portsc & PORT_PE)) + /* * While most USB host controllers implement their registers in * little-endian format, a minority (celleb companion chip) implement
Some NXP processor using chipidea IP has a bug when frame babble is detected. As per 4.15.1.1.1 Serial Bus Babble: A babble condition also exists if IN transaction is in progress at High-speed SOF2 point. This is called frame balle. The host controller must disable the port to which the frame babble is detected. The USB controller has disabled the port (PE cleared) and has asserted USBERRINT when frame babble is detected, but PEC is not asserted. Therefore, the SW didn't aware that port has been disabled. Then the SW keeps sending packets to this port, but all of the transfers will fail. This workaround will firstly assert PCD by SW when USBERRINT is detected and then judge whether port change has really occurred or not by polling roothub status. Because the PEC doesn't get asserted in our case, this patch will also assert it by SW when specific conditions are satisfied. Signed-off-by: Xu Yang <xu.yang_2@nxp.com> --- drivers/usb/host/ehci-hcd.c | 5 +++++ drivers/usb/host/ehci-hub.c | 10 +++++++++- drivers/usb/host/ehci.h | 10 ++++++++++ 3 files changed, 24 insertions(+), 1 deletion(-)