From: Dmitry Osipenko Date: Tue, 19 Jan 2021 23:52:10 +0000 (+0300) Subject: memory: tegra: Check whether reset is already asserted X-Git-Tag: v5.12-rc1~194^2~12^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6ce84ab6492c8634039267d1d9e89fe41dcd4770;p=thirdparty%2Fkernel%2Flinux.git 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 --- diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c index 44064de962c2f..a21163ccadc40 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);