6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Erico Nunes <nunes.erico@xxxxxxxxx> [ 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@xxxxxxxxx> Signed-off-by: Qiang Yu <yuq825@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20240124025947.2110659-5-nunes.erico@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 ca3842f719842..82071835ec9ed 100644 --- a/drivers/gpu/drm/lima/lima_gp.c +++ b/drivers/gpu/drm/lima/lima_gp.c @@ -166,6 +166,11 @@ 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); @@ -179,6 +184,13 @@ 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) { -- 2.43.0
