[PATCH] Xilinx: hwicap: cleanup polling timeout.

[Stephen Neuendorffer]

In order to avoid polling forever if an error occurs, this driver
includes a timeout counter.  However, in fast systems, this counter
wasn't high enough.  This patch fixes the bug and also makes the
buffer-based and fifo-based drivers return the same error condition on
a timeout (-EIO).

Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer at xilinx.com>
---
 drivers/char/xilinx_hwicap/buffer_icap.c   |   10 ++++++++--
 drivers/char/xilinx_hwicap/fifo_icap.c     |    9 +++++++++
 drivers/char/xilinx_hwicap/xilinx_hwicap.h |    3 ---
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/char/xilinx_hwicap/buffer_icap.c b/drivers/char/xilinx_hwicap/buffer_icap.c
index aa7f796..0993883 100644
--- a/drivers/char/xilinx_hwicap/buffer_icap.c
+++ b/drivers/char/xilinx_hwicap/buffer_icap.c
@@ -35,6 +35,12 @@
 
 #include "buffer_icap.h"
 
+/* Number of times to poll the done register.  This has to be large
+   enough to allow an entire configuration to complete. If an entire
+   page (4kb) is configured at once, that could take up to 4k cycles
+   with a byte-wide icap interface. */
+#define XHI_MAX_RETRIES     5000
+
 /* Indicates how many bytes will fit in a buffer. (1 BRAM) */
 #define XHI_MAX_BUFFER_BYTES        2048
 #define XHI_MAX_BUFFER_INTS         (XHI_MAX_BUFFER_BYTES >> 2)
@@ -208,7 +214,7 @@ static int buffer_icap_device_read(struct hwicap_drvdata *drvdata,
 	while (buffer_icap_busy(base_address)) {
 		retries++;
 		if (retries > XHI_MAX_RETRIES)
-			return -EBUSY;
+			return -EIO;
 	}
 	return 0;
 
@@ -242,7 +248,7 @@ static int buffer_icap_device_write(struct hwicap_drvdata *drvdata,
 	while (buffer_icap_busy(base_address)) {
 		retries++;
 		if (retries > XHI_MAX_RETRIES)
-			return -EBUSY;
+			return -EIO;
 	}
 	return 0;
 
diff --git a/drivers/char/xilinx_hwicap/fifo_icap.c b/drivers/char/xilinx_hwicap/fifo_icap.c
index 776b505..d1cd928 100644
--- a/drivers/char/xilinx_hwicap/fifo_icap.c
+++ b/drivers/char/xilinx_hwicap/fifo_icap.c
@@ -35,6 +35,15 @@
 
 #include "fifo_icap.h"
 
+/* Number of times to poll the done register.  This has to be large
+ * enough to allow an entire configuration to complete.  If an entire
+ * page (4kb) is configured at once, that could take up to 4k cycles
+ * with a byte-wide icap interface.  In most cases, this driver is
+ * used with a much smaller fifo, but this should be sufficient in the
+ * worst case.
+ */
+#define XHI_MAX_RETRIES     5000
+
 /* Register offsets for the XHwIcap device. */
 #define XHI_GIER_OFFSET	0x1C  /* Device Global Interrupt Enable Reg */
 #define XHI_IPISR_OFFSET 0x20  /* Interrupt Status Register */
diff --git a/drivers/char/xilinx_hwicap/xilinx_hwicap.h b/drivers/char/xilinx_hwicap/xilinx_hwicap.h
index 1f9c8b0..fd4be31 100644
--- a/drivers/char/xilinx_hwicap/xilinx_hwicap.h
+++ b/drivers/char/xilinx_hwicap/xilinx_hwicap.h
@@ -89,9 +89,6 @@ struct hwicap_driver_config {
 	void (*reset)(struct hwicap_drvdata *drvdata);
 };
 
-/* Number of times to poll the done regsiter */
-#define XHI_MAX_RETRIES     10
-
 /************ Constant Definitions *************/
 
 #define XHI_PAD_FRAMES              0x1
-- 
1.5.3.4-dirty