From 1703a6d3c38944731ba23594843a704d828266f3 Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Tue, 25 May 2010 05:36:52 +0100 Subject: [PATCH] USB: s3c-hsotg: Ensure FIFOs are fully flushed after layout 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/s3c-hsotg.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c index 31d19e1f261d..26193eceb323 100644 --- a/drivers/usb/gadget/s3c-hsotg.c +++ b/drivers/usb/gadget/s3c-hsotg.c @@ -300,6 +300,7 @@ 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 @@ -335,6 +336,31 @@ 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); } /** -- 2.20.1