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authorBen Dooks <ben-linux@fluff.org>2010-05-25 05:36:52 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2010-06-04 13:16:19 -0700
commit1703a6d3c38944731ba23594843a704d828266f3 (patch)
treeac9907c3100e98e1626e1d3b2675913c27b69c76
parent2e0e0777ec2ea1cb5461bded2c09573a9d778622 (diff)
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 <ben-linux@fluff.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/gadget/s3c-hsotg.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index 31d19e1f261..26193eceb32 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);
}
/**