[PATCH 3/3] venus: firmware: Correct assertion of reset bit on remote processor

From: Stanimir Varbanov
Date: Wed Oct 05 2022 - 04:38:14 EST


Currently we use read/write_relaxed in combination with mb() to assert
reset. This looks wrong because mb() after write_relaxed() will not
order correctly load-update-store sequence. Correct this by use
readl/writel which include memory barriers.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
---
drivers/media/platform/qcom/venus/firmware.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/media/platform/qcom/venus/firmware.c b/drivers/media/platform/qcom/venus/firmware.c
index 71e43611d1cf..142d4c74017c 100644
--- a/drivers/media/platform/qcom/venus/firmware.c
+++ b/drivers/media/platform/qcom/venus/firmware.c
@@ -181,17 +181,15 @@ static int venus_shutdown_no_tz(struct venus_core *core)

if (IS_V6(core)) {
/* Assert the reset to XTSS */
- reg = readl_relaxed(wrapper_tz_base + WRAPPER_TZ_XTSS_SW_RESET);
+ reg = readl(wrapper_tz_base + WRAPPER_TZ_XTSS_SW_RESET);
reg |= WRAPPER_XTSS_SW_RESET_BIT;
- writel_relaxed(reg, wrapper_tz_base + WRAPPER_TZ_XTSS_SW_RESET);
+ writel(reg, wrapper_tz_base + WRAPPER_TZ_XTSS_SW_RESET);
} else {
/* Assert the reset to ARM9 */
- reg = readl_relaxed(wrapper_base + WRAPPER_A9SS_SW_RESET);
+ reg = readl(wrapper_base + WRAPPER_A9SS_SW_RESET);
reg |= WRAPPER_A9SS_SW_RESET_BIT;
- writel_relaxed(reg, wrapper_base + WRAPPER_A9SS_SW_RESET);
+ writel(reg, wrapper_base + WRAPPER_A9SS_SW_RESET);
}
- /* Make sure reset is asserted before the mapping is removed */
- mb();

iommu = core->fw.iommu_domain;

--
2.25.1