According to the design guide, if the FIFO layout is changed, then the FIFOs must be flushed to ensure all FIFO pointers are correct.
Signed-off-by: Ben Dooks <[email protected]> --- drivers/usb/gadget/s3c-hsotg.c | 27 +++++++++++++++++++++++++++ 1 files changed, 27 insertions(+), 0 deletions(-) diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c index 215beae..bce510c 100644 --- a/drivers/usb/gadget/s3c-hsotg.c +++ b/drivers/usb/gadget/s3c-hsotg.c @@ -301,6 +301,7 @@ static void s3c_hsotg_init_fifo(struct s3c_hsotg *hsotg) unsigned int ep; unsigned int addr; unsigned int size; + int timeout; u32 val; /* the ryu 2.6.24 release ahs @@ -338,6 +339,32 @@ static void s3c_hsotg_init_fifo(struct s3c_hsotg *hsotg) writel(val, hsotg->regs + S3C_DPTXFSIZn(ep)); } + + /* according to p428 of the design guide, we need to ensure that + * all fifos are flushed before continuing. + */ + + writel(S3C_GRSTCTL_TxFNum(0x10) | S3C_GRSTCTL_TxFFlsh | + S3C_GRSTCTL_RxFFlsh, hsotg->regs + S3C_GRSTCTL); + + /* wait until the fifos are both flushed */ + timeout = 100; + while (1) { + val = readl(hsotg->regs + S3C_GRSTCTL); + + if ((val & (S3C_GRSTCTL_TxFFlsh | S3C_GRSTCTL_RxFFlsh)) == 0) + break; + + if (--timeout == 0) { + dev_err(hsotg->dev, + "%s: timeout flushing fifos (GRSTCTL=%08x)\n", + __func__, val); + } + + udelay(1); + } + + dev_dbg(hsotg->dev, "FIFOs reset, timeout at %d\n", timeout); } /** -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
