From 6ce84ab6492c8634039267d1d9e89fe41dcd4770 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Wed, 20 Jan 2021 02:52:10 +0300 Subject: memory: tegra: Check whether reset is already asserted 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 # Ouya T30 Tested-by: Nicolas Chauvet # PAZ00 T20 Tested-by: Matt Merhar # Ouya T30 Signed-off-by: Dmitry Osipenko Link: https://lore.kernel.org/r/20210119235210.13006-1-digetx@gmail.com Signed-off-by: Krzysztof Kozlowski --- drivers/memory/tegra/mc.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/memory') 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); -- cgit v1.2.3-59-g8ed1b