5.4-stable review patch. If anyone has any objections, please let me know.
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From: Erico Nunes nunes.erico@gmail.com
[ Upstream commit 27aa58ec85f973d98d336df7b7941149308db80f ]
This is required for reliable hard resets. Otherwise, doing a hard reset while a task is still running (such as a task which is being stopped by the drm_sched timeout handler) may result in random mmu write timeouts or lockups which cause the entire gpu to hang.
Signed-off-by: Erico Nunes nunes.erico@gmail.com Signed-off-by: Qiang Yu yuq825@gmail.com Link: https://patchwork.freedesktop.org/patch/msgid/20240124025947.2110659-5-nunes... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/lima/lima_gp.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/lima/lima_gp.c b/drivers/gpu/drm/lima/lima_gp.c index 3fca560087c97..4bf216cb33030 100644 --- a/drivers/gpu/drm/lima/lima_gp.c +++ b/drivers/gpu/drm/lima/lima_gp.c @@ -138,6 +138,11 @@ static void lima_gp_task_run(struct lima_sched_pipe *pipe, gp_write(LIMA_GP_CMD, cmd); }
+static int lima_gp_bus_stop_poll(struct lima_ip *ip) +{ + return !!(gp_read(LIMA_GP_STATUS) & LIMA_GP_STATUS_BUS_STOPPED); +} + static int lima_gp_hard_reset_poll(struct lima_ip *ip) { gp_write(LIMA_GP_PERF_CNT_0_LIMIT, 0xC01A0000); @@ -151,6 +156,13 @@ static int lima_gp_hard_reset(struct lima_ip *ip)
gp_write(LIMA_GP_PERF_CNT_0_LIMIT, 0xC0FFE000); gp_write(LIMA_GP_INT_MASK, 0); + + gp_write(LIMA_GP_CMD, LIMA_GP_CMD_STOP_BUS); + ret = lima_poll_timeout(ip, lima_gp_bus_stop_poll, 10, 100); + if (ret) { + dev_err(dev->dev, "%s bus stop timeout\n", lima_ip_name(ip)); + return ret; + } gp_write(LIMA_GP_CMD, LIMA_GP_CMD_RESET); ret = lima_poll_timeout(ip, lima_gp_hard_reset_poll, 10, 100); if (ret) {