> -----Original Message----- > From: Alan Stern [mailto:stern@xxxxxxxxxxxxxxxxxxx] > Sent: Friday, July 31, 2015 10:04 PM > To: Badola Nikhil-B46172 > Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; > gregkh@xxxxxxxxxxxxxxxxxxx; Mehresh Ramneek-B31383 > Subject: Re: [PATCH] drivers: usb: fsl: Workaround for USB erratum-A005275 > > On Fri, 31 Jul 2015, Nikhil Badola wrote: > > > Incoming packets in high speed are randomly corrupted by h/w resulting > > in multiple errors. This workaround makes FS as default mode in all > > affected socs by disabling HS chirp signalling.This errata does not > > affect FS and LS mode. > > > > Forces all HS devices to connect in FS mode for all socs affected by > > this erratum: > > P3041 and P2041 rev 1.0 and 1.1 > > P5020 and P5010 rev 1.0 and 2.0 > > P5040, P1010 and T4240 rev 1.0 > > Ooh, that's a really bad bug. People will be pretty annoyed that they can't > use high speed connections. > > > --- a/drivers/usb/host/ehci-hub.c > > +++ b/drivers/usb/host/ehci-hub.c > > @@ -1222,6 +1222,13 @@ int ehci_hub_control( > > ehci->reset_done [wIndex] = jiffies > > + msecs_to_jiffies (50); > > } > > + > > + /* Force full-speed connect for FSL high-speed > erratum; > > + * disable HS Chirp by setting PFSC bit > > + */ > > + if (ehci_has_fsl_hs_errata(ehci)) > > + temp |= (1 << PORTSC_FSL_PFSC); > > + > > This hunk was added in the wrong place. It should come before the closing '}' > above, not after. That's because you don't want to force a full-speed > connection if the device is already using low speed. I agree that the hunk must be added before '}' i.e. in else block but reason being our controllers have tt . Please correct me if I am wrong. However the code executes "else" block in case of high speed as well as low speed device, and low speed device is working fine in that case (I checked a Dell USB Keyboard). > > > --- a/drivers/usb/host/ehci.h > > +++ b/drivers/usb/host/ehci.h > > @@ -215,6 +215,7 @@ struct ehci_hcd { /* one per > controller */ > > /* SILICON QUIRKS */ > > unsigned no_selective_suspend:1; > > unsigned has_fsl_port_bug:1; /* FreeScale */ > > + unsigned has_fsl_hs_errata:1; /* Freescale HS quirk > */ > > unsigned big_endian_mmio:1; > > unsigned big_endian_desc:1; > > unsigned big_endian_capbase:1; > > @@ -675,6 +676,17 @@ ehci_port_speed(struct ehci_hcd *ehci, unsigned > int portsc) > > #define ehci_port_speed(ehci, portsc) > USB_PORT_STAT_HIGH_SPEED > > #endif > > > > +#define PORTSC_FSL_PFSC 24 /* Port Force Full-Speed Connect */ > > + > > +#if defined(CONFIG_PPC_85xx) > > +/* Some Freescale processors have an erratum (USB A-005275) in which > > + * incoming packets get corrupted in HS mode */ > > +#define ehci_has_fsl_hs_errata(e) ((e)->has_fsl_hs_errata) > > +#else > > +#define ehci_has_fsl_hs_errata(e) (0) > > +#endif > > + > > > > /*-------------------------------------------------------------------- > > -----*/ > > I would prefer it if you add your new hunk after this /*-----...---*/ dividing > line (that is, next to the ehci_has_fsl_portno_bug() code) instead of before > the dividing line. Agreed. Will make changes in next version. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
