[PATCH V2] gpu: host1x: handle the correct # of syncpt regs

Stephen Warren
2014-04-04T22:31:05Z

From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

BIT_WORD() truncates rather than rounds, so the loops in
syncpt_thresh_isr() and _host1x_intr_disable_all_syncpt_intrs() use <=
rather than < in an attempt to process the correct number of registers
when rounding of the conversion of count of bits to count of words is
necessary. However, when rounding isn't necessary because the value is
already a multiple of the divisor (as is the case for all values of
nb_pts the code actually sees), this causes one too many registers to
be processed.

Solve this by using and explicit DIV_ROUND_UP() call, rather than
BIT_WORD(), and comparing with < rather than <=.

Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
v2: Use DIV_ROUND_UP rather than BITS_TO_LONGS to avoid problems on 64-bit.
---
drivers/gpu/host1x/hw/intr_hw.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/host1x/hw/intr_hw.c b/drivers/gpu/host1x/hw/intr_hw.c
index db9017adfe2b..498b37e39058 100644
--- a/drivers/gpu/host1x/hw/intr_hw.c
+++ b/drivers/gpu/host1x/hw/intr_hw.c
@@ -47,7 +47,7 @@ static irqreturn_t syncpt_thresh_isr(int irq, void *dev_id)
unsigned long reg;
int i, id;

- for (i = 0; i <= BIT_WORD(host->info->nb_pts); i++) {
+ for (i = 0; i < DIV_ROUND_UP(host->info->nb_pts, 32); i++) {
reg = host1x_sync_readl(host,
HOST1X_SYNC_SYNCPT_THRESH_CPU0_INT_STATUS(i));
for_each_set_bit(id, &reg, BITS_PER_LONG) {
@@ -64,7 +64,7 @@ static void _host1x_intr_disable_all_syncpt_intrs(struct host1x *host)
{
u32 i;

- for (i = 0; i <= BIT_WORD(host->info->nb_pts); ++i) {
+ for (i = 0; i < DIV_ROUND_UP(host->info->nb_pts, 32); ++i) {
host1x_sync_writel(host, 0xffffffffu,
HOST1X_SYNC_SYNCPT_THRESH_INT_DISABLE(i));
host1x_sync_writel(host, 0xffffffffu,
--
1.8.1.5