From: Ben Dooks <ben-linux@xxxxxxxxx>
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 <ben-linux@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/gadget/s3c-hsotg.c | 26 ++++++++++++++++++++++++++
1 files changed, 26 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index 31d19e1..26193ec 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);
}
/**
--
1.7.1
--
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