Check whether memory client reset is already asserted in order to prevent
DMA-flush error on trying to re-assert an already asserted reset.
This becomes a problem once PMC GENPD is enabled to use memory resets
since GENPD will get a error and fail to toggle power domain. PMC GENPDs
can't be toggled safely without holding memory reset on Tegra and we're
about to fix this.
Tested-by: Peter Geis <pgwipeout@xxxxxxxxx> # Ouya T30
Tested-by: Dmitry Osipenko <digetx@xxxxxxxxx> # A500 T20 and Nexus7 T30
Tested-by: Nicolas Chauvet <kwizart@xxxxxxxxx> # PAZ00 T20
Tested-by: Matt Merhar <mattmerhar@xxxxxxxxxxxxxx> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
drivers/memory/tegra/mc.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 44064de962c2..a21163ccadc4 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -176,6 +176,13 @@ static int tegra_mc_hotreset_assert(struct reset_controller_dev *rcdev,
if (!rst_ops)
return -ENODEV;
+ /* DMA flushing will fail if reset is already asserted */
+ if (rst_ops->reset_status) {
+ /* check whether reset is asserted */
+ if (rst_ops->reset_status(mc, rst))
+ return 0;
+ }
+
if (rst_ops->block_dma) {
/* block clients DMA requests */
err = rst_ops->block_dma(mc, rst);
--
2.29.2
