fsi/fsi-master-gpio: Reduce dpoll clocks

FSI_GPIO_DPOLL_CLOCKS is the number of clocks before sending
a DPOLL command after receiving a BUSY status. It should be
at least tSendDelay (16 clocks).

According to comments in the code, it needs to also be at least
21 clocks due to HW issues.

It's currently 100 clocks which impacts performances negatively
in some cases. Reduces it in half to 50 clocks which seems to
still be solid.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>

diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c
index 029b0a5b6d89ffa0353096189635546a4757f62b..bd2b2cbd5eb527d0e3ef6ff4b149198537c0d156 100644 (file)
--- a/drivers/fsi/fsi-master-gpio.c
+++ b/drivers/fsi/fsi-master-gpio.c
@@ -29,7 +29,8 @@
 #define        FSI_GPIO_CMD_TERM       0x3f
 #define FSI_GPIO_CMD_ABS_AR    0x4
 
-#define        FSI_GPIO_DPOLL_CLOCKS   100      /* < 21 will cause slave to hang */
+
+#define        FSI_GPIO_DPOLL_CLOCKS   50      /* < 21 will cause slave to hang */
 
 /* Bus errors */
 #define        FSI_GPIO_ERR_BUSY       1       /* Slave stuck in busy state */
@@ -43,7 +44,7 @@
 #define        FSI_GPIO_RESP_ACK       0
 #define        FSI_GPIO_RESP_ACKD      4
 
-#define        FSI_GPIO_MAX_BUSY       100
+#define        FSI_GPIO_MAX_BUSY       200
 #define        FSI_GPIO_MTOE_COUNT     1000
 #define        FSI_GPIO_DRAIN_BITS     20
 #define        FSI_GPIO_CRC_SIZE       4