On 4/5/20 1:35 PM, Dmitry Osipenko wrote:
External email: Use caution opening links or attachments 04.04.2020 04:25, Sowjanya Komatineni пишет: ...+static int tegra_channel_capture_frame(struct tegra_vi_channel *chan, + struct tegra_channel_buffer *buf) +{ + int err = 0; + u32 thresh, value, frame_start, mw_ack_done; + int bytes_per_line = chan->format.bytesperline; + + /* program buffer address by using surface 0 */ + vi_csi_write(chan, TEGRA_VI_CSI_SURFACE0_OFFSET_MSB, + (u64)buf->addr >> 32); + vi_csi_write(chan, TEGRA_VI_CSI_SURFACE0_OFFSET_LSB, buf->addr); + vi_csi_write(chan, TEGRA_VI_CSI_SURFACE0_STRIDE, bytes_per_line); + + /* + * Tegra VI block interacts with host1x syncpt for synchronizing + * programmed condition of capture state and hardware operation. + * Frame start and Memory write acknowledge syncpts has their own + * FIFO of depth 2. + * + * Syncpoint trigger conditions set through VI_INCR_SYNCPT register + * are added to HW syncpt FIFO and when the HW triggers, syncpt + * condition is removed from the FIFO and counter at syncpoint index + * will be incremented by the hardware and software can wait for + * counter to reach threshold to synchronize capturing frame with the + * hardware capture events. + */ + + /* increase channel syncpoint threshold for FRAME_START */ + thresh = host1x_syncpt_incr_max(chan->frame_start_sp, 1); + + /* Program FRAME_START trigger condition syncpt request */ + frame_start = VI_CSI_PP_FRAME_START(chan->portno); + value = VI_CFG_VI_INCR_SYNCPT_COND(frame_start) | + host1x_syncpt_id(chan->frame_start_sp); + tegra_vi_write(chan, TEGRA_VI_CFG_VI_INCR_SYNCPT, value); + + /* increase channel syncpoint threshold for MW_ACK_DONE */ + buf->mw_ack_sp_thresh = host1x_syncpt_incr_max(chan->mw_ack_sp, 1); + + /* Program MW_ACK_DONE trigger condition syncpt request */ + mw_ack_done = VI_CSI_MW_ACK_DONE(chan->portno); + value = VI_CFG_VI_INCR_SYNCPT_COND(mw_ack_done) | + host1x_syncpt_id(chan->mw_ack_sp); + tegra_vi_write(chan, TEGRA_VI_CFG_VI_INCR_SYNCPT, value); + + /* enable single shot capture */ + vi_csi_write(chan, TEGRA_VI_CSI_SINGLE_SHOT, SINGLE_SHOT_CAPTURE); + chan->capture_reqs++; + + /* wait for syncpt counter to reach frame start event threshold */ + err = host1x_syncpt_wait(chan->frame_start_sp, thresh, + TEGRA_VI_SYNCPT_WAIT_TIMEOUT, &value); + if (err) { + dev_err(&chan->video.dev, + "frame start syncpt timeout: %d\n", err); + /* increment syncpoint counter for timedout events */ + host1x_syncpt_incr(chan->frame_start_sp);Why incrementing is done while hardware is still active? The sync point's state needs to be completely reset after resetting hardware. But I don't think that the current upstream host1x driver supports doing that, it's one of the known-long-standing problems of the host1x driver. At least the sp->max_val incrementing should be done based on the actual syncpoint value and this should be done after resetting hardware.
upstream host1x driver don't have API to reset or to equalize max value with min/load value.
So to synchronize missed event, incrementing HW syncpt counter. This should not impact as we increment this in case of missed events only.
+ spin_lock(&chan->sp_incr_lock); + host1x_syncpt_incr(chan->mw_ack_sp); + spin_unlock(&chan->sp_incr_lock); + /* clear errors and recover */ + tegra_channel_capture_error_recover(chan); + release_buffer(chan, buf, VB2_BUF_STATE_ERROR); + return err; + }
