[U-Boot] [PATCH] drivers: usb: fsl: Workaround for Erratum A004477

nikhil.badola at freescale.com nikhil.badola at freescale.com
Fri Apr 10 05:29:10 CEST 2015


> -----Original Message-----
> From: Albert ARIBAUD [mailto:albert.u.boot at aribaud.net]
> Sent: Friday, November 21, 2014 6:00 PM
> To: Badola Nikhil-B46172
> Cc: u-boot at lists.denx.de
> Subject: Re: [U-Boot] [PATCH] drivers: usb: fsl: Workaround for Erratum
> A004477
> 
> Hello Nikhil,
> 
> On Fri, 21 Nov 2014 17:25:21 +0530, Nikhil Badola
> <nikhil.badola at freescale.com> wrote:
> > Add a delay of 1 microsecond before issuing soft reset to the
> > controller to let ongoing ULPI transaction complete.
> > This prevents corruption of ULPI Function Control Register which
> > eventually prevents phy clock from entering to low power mode
> >
> > Signed-off-by: Nikhil Badola <nikhil.badola at freescale.com>
> > ---
> > 	Depends on patch https://patchwork.ozlabs.org/patch/404879/
> >
> >  arch/powerpc/cpu/mpc85xx/cmd_errata.c     |  4 ++++
> >  arch/powerpc/include/asm/config_mpc85xx.h |  6 ++++++
> >  drivers/usb/host/ehci-fsl.c               | 10 ++++++++++
> >  include/fsl_usb.h                         | 29 +++++++++++++++++++++++++++++
> >  4 files changed, 49 insertions(+)
> >
> > diff --git a/arch/powerpc/cpu/mpc85xx/cmd_errata.c
> > b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
> > index fe3eb06..bc59352 100644
> > --- a/arch/powerpc/cpu/mpc85xx/cmd_errata.c
> > +++ b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
> > @@ -298,6 +298,10 @@ static int do_errata(cmd_tbl_t *cmdtp, int flag, int
> argc, char * const argv[])
> >  	if (has_erratum_a007798())
> >  		puts("Work-around for Erratum A007798 enabled\n");
> #endif
> > +#ifdef CONFIG_SYS_FSL_ERRATUM_A004477
> > +	if (has_erratum_a004477())
> > +		puts("Work-around for Erratum A004477 enabled\n"); #endif
> >  #ifdef CONFIG_SYS_FSL_ERRATUM_I2C_A004447
> >  	if ((SVR_SOC_VER(svr) == SVR_8548 && IS_SVR_REV(svr, 3, 1)) ||
> >  	    (SVR_REV(svr) <= CONFIG_SYS_FSL_A004447_SVR_REV)) diff --git
> > a/arch/powerpc/include/asm/config_mpc85xx.h
> > b/arch/powerpc/include/asm/config_mpc85xx.h
> > index 7860b40..fe9e9c1 100644
> > --- a/arch/powerpc/include/asm/config_mpc85xx.h
> > +++ b/arch/powerpc/include/asm/config_mpc85xx.h
> > @@ -161,6 +161,7 @@
> >  #define CONFIG_SYS_FSL_ERRATUM_A004508  #define
> > CONFIG_SYS_FSL_ERRATUM_A007075  #define
> CONFIG_SYS_FSL_ERRATUM_A006261
> > +#define CONFIG_SYS_FSL_ERRATUM_A004477
> >  #define CONFIG_SYS_FSL_A004447_SVR_REV	0x10
> >  #define CONFIG_ESDHC_HC_BLK_ADDR
> >
> > @@ -292,6 +293,7 @@
> >  #define CONFIG_FSL_SATA_ERRATUM_A001
> >  #define CONFIG_SYS_FSL_ERRATUM_A004508  #define
> > CONFIG_SYS_FSL_ERRATUM_A005125
> > +#define CONFIG_SYS_FSL_ERRATUM_A004477
> >
> >  #elif defined(CONFIG_P1023)
> >  #define CONFIG_MAX_CPUS			2
> > @@ -372,6 +374,7 @@
> >  #define CONFIG_SYS_FSL_SRIO_MSG_UNIT_NUM	2
> >  #define CONFIG_SYS_FSL_ERRATUM_A004508  #define
> > CONFIG_SYS_FSL_ERRATUM_A005125
> > +#define CONFIG_SYS_FSL_ERRATUM_A004477
> >  #define CONFIG_USB_MAX_CONTROLLER_COUNT	1
> >
> >  #elif defined(CONFIG_PPC_P2041) /* also supports P2040 */ @@ -589,6
> > +592,7 @@  #define CONFIG_NAND_FSL_IFC  #define
> > CONFIG_SYS_FSL_ERRATUM_ESDHC111  #define
> > CONFIG_SYS_FSL_ERRATUM_A005125
> > +#define CONFIG_SYS_FSL_ERRATUM_A004477
> >  #define CONFIG_ESDHC_HC_BLK_ADDR
> >
> >  #elif defined(CONFIG_BSC9132)
> > @@ -613,6 +617,7 @@
> >  #define CONFIG_SYS_FSL_PCIE_COMPAT	"fsl,qoriq-pcie-v2.2"
> >  #define CONFIG_SYS_FSL_ERRATUM_A005125  #define
> > CONFIG_SYS_FSL_ERRATUM_A005434
> > +#define CONFIG_SYS_FSL_ERRATUM_A004477
> >  #define CONFIG_SYS_FSL_ERRATUM_I2C_A004447
> >  #define CONFIG_SYS_FSL_A004447_SVR_REV	0x11
> >  #define CONFIG_ESDHC_HC_BLK_ADDR
> > @@ -712,6 +717,7 @@
> >  #define CONFIG_SYS_FSL_ERRATUM_A006475  #define
> > CONFIG_SYS_FSL_ERRATUM_A006384  #define
> CONFIG_SYS_FSL_ERRATUM_A007212
> > +#define CONFIG_SYS_FSL_ERRATUM_A004477
> >  #define CONFIG_SYS_CCSRBAR_DEFAULT	0xfe000000
> >  #define CONFIG_SYS_FSL_SFP_VER_3_0
> >
> > diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
> > index 5d4288d..41ff1a7 100644
> > --- a/drivers/usb/host/ehci-fsl.c
> > +++ b/drivers/usb/host/ehci-fsl.c
> > @@ -138,6 +138,16 @@ int ehci_hcd_init(int index, enum usb_init_type
> init,
> >  	if (has_erratum_a007798())
> >  		set_txfifothresh(ehci, TXFIFOTHRESH);
> >
> > +	if (has_erratum_a004477()) {
> > +		/*
> > +		 * When reset is issued while any ULPI transaction is ongoing
> > +		 * then it may result to corruption of ULPI Function Control
> > +		 * Register which eventually causes phy clock to enter low
> > +		 * power mode which stops the clock. Thus delay is required
> > +		 * before reset to let ongoing ULPI transaction complete.
> 
> Actually the erratum suggests checking transaction status before issuing a
> soft reset. Here, could the code do this check and wait for the transation to
> finish, rather than wait for an arbitrary duration?

There have been discussions with IP team for changing the suggested workaround.
The erratum talks about the ULPI transactions i.e from controller to ULPI phy and not 
the USB schedule transactions .Hence halting the controller before soft reset isn't the 
correct workaround.
In addition, as per the current flow of usb start/reset, the controller is always in halt set 
before issuing soft reset. This is taken care by usb_stop().

Regarding the delay of 1 microsecond( minimum delay), it seems to be sufficient for ULPI 
Transactions to complete as ULPI interface runs on 60Mhz clock.

> 
> > +		 */
> > +		udelay(1);
> > +	}
> >  	return 0;
> >  }
> >
> > diff --git a/include/fsl_usb.h b/include/fsl_usb.h index
> > d251f5d..88d8a8b 100644
> > --- a/include/fsl_usb.h
> > +++ b/include/fsl_usb.h
> > @@ -164,6 +164,30 @@ static inline bool has_erratum_a007792(void)
> >  	return false;
> >  }
> >
> > +static inline bool has_erratum_a004477(void) {
> > +	u32 svr = get_svr();
> > +	u32 soc = SVR_SOC_VER(svr);
> > +
> > +	switch (soc) {
> > +	case SVR_P1010:
> > +		return IS_SVR_REV(svr, 1, 0) || IS_SVR_REV(svr, 2, 0);
> > +	case SVR_P1022:
> > +	case SVR_9131:
> > +	case SVR_9132:
> > +		return IS_SVR_REV(svr, 1, 0) || IS_SVR_REV(svr, 1, 1);
> > +	case SVR_P2020:
> > +		return IS_SVR_REV(svr, 1, 0) || IS_SVR_REV(svr, 2, 0) ||
> > +			IS_SVR_REV(svr, 2, 1);
> > +	case SVR_B4860:
> > +	case SVR_B4420:
> > +		return IS_SVR_REV(svr, 1, 0) || IS_SVR_REV(svr, 2, 0);
> > +	case SVR_P4080:
> > +		return IS_SVR_REV(svr, 2, 0) || IS_SVR_REV(svr, 3, 0);
> > +	}
> > +
> > +	return false;
> > +}
> >  #else
> >  static inline bool has_erratum_a006261(void)  { @@ -184,5 +208,10 @@
> > static inline bool has_erratum_a007792(void)  {
> >  	return false;
> >  }
> > +
> > +static inline bool has_erratum_a004477(void) {
> > +	return false;
> > +}
> >  #endif
> >  #endif /*_ASM_FSL_USB_H_ */
> > --
> > 1.7.11.7
> >
> >
> > _______________________________________________
> > U-Boot mailing list
> > U-Boot at lists.denx.de
> > http://lists.denx.de/mailman/listinfo/u-boot
> 
> 
> 
> Amicalement,
> --
> Albert.


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