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-rw-r--r--drivers/ddr/altera/sequencer.c18
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/ddr/altera/sequencer.c b/drivers/ddr/altera/sequencer.c
index 5a6c99188a..25de209b5d 100644
--- a/drivers/ddr/altera/sequencer.c
+++ b/drivers/ddr/altera/sequencer.c
@@ -767,8 +767,10 @@ static void delay_for_n_mem_clocks(const u32 clocks)
debug("%s:%d: clocks=%u ... start\n", __func__, __LINE__, clocks);
- /* scale (rounding up) to get afi clocks */
+ /* Scale (rounding up) to get afi clocks. */
afi_clocks = DIV_ROUND_UP(clocks, AFI_RATE_RATIO);
+ if (afi_clocks) /* Temporary underflow protection */
+ afi_clocks--;
/*
* Note, we don't bother accounting for being off a little
@@ -779,18 +781,18 @@ static void delay_for_n_mem_clocks(const u32 clocks)
*/
if (afi_clocks == 0) {
;
- } else if (afi_clocks <= 0x100) {
- inner = afi_clocks - 1;
+ } else if (afi_clocks < 0x100) {
+ inner = afi_clocks;
outer = 0;
c_loop = 0;
- } else if (afi_clocks <= 0x10000) {
+ } else if (afi_clocks < 0x10000) {
inner = 0xff;
- outer = (afi_clocks - 1) >> 8;
+ outer = afi_clocks >> 8;
c_loop = 0;
- } else {
+ } else { /* >= 0x10000 */
inner = 0xff;
outer = 0xff;
- c_loop = (afi_clocks - 1) >> 16;
+ c_loop = afi_clocks >> 16;
}
/*
@@ -810,7 +812,7 @@ static void delay_for_n_mem_clocks(const u32 clocks)
* and sequencer rom and keeps the delays more accurate and reduces
* overhead
*/
- if (afi_clocks <= 0x100) {
+ if (afi_clocks < 0x100) {
writel(SKIP_DELAY_LOOP_VALUE_OR_ZERO(inner),
&sdr_rw_load_mgr_regs->load_cntr1);