16.12.2021 20:11, Akhil R пишет:

+static int tegra_dma_terminate_all(struct dma_chan *dc)
+{
+	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
+	unsigned long wcount = 0;
+	unsigned long status;
+	unsigned long flags;
+	int err;
+
+	raw_spin_lock_irqsave(&tdc->lock, flags);
+
+	if (!tdc->dma_desc) {
+		raw_spin_unlock_irqrestore(&tdc->lock, flags);
+		return 0;
+	}
+
+	if (!tdc->busy)
+		goto skip_dma_stop;
+
+	if (tdc->tdma->chip_data->hw_support_pause)
+		err = tegra_dma_pause(tdc);
+	else
+		err = tegra_dma_stop_client(tdc);
+
+	if (err) {
+		raw_spin_unlock_irqrestore(&tdc->lock, flags);
+		return err;
+	}
+
+	status = tdc_read(tdc, TEGRA_GPCDMA_CHAN_STATUS);
+	if (status & TEGRA_GPCDMA_STATUS_ISE_EOC) {
+		dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
+		tegra_dma_xfer_complete(tdc);
+		status = tdc_read(tdc, TEGRA_GPCDMA_CHAN_STATUS);
+	}
+
+	wcount = tdc_read(tdc, TEGRA_GPCDMA_CHAN_XFER_COUNT);
+	tegra_dma_stop(tdc);
+
+	tdc->dma_desc->bytes_transferred +=
+			tdc->dma_desc->bytes_requested - (wcount * 4);
+
+skip_dma_stop:
+	tegra_dma_sid_free(tdc);
+	vchan_free_chan_resources(&tdc->vc);
+	kfree(&tdc->vc);

You really going to kfree the head of tegra_dma_channel here? Once
again, this code was 100% untested :/

You're not allowed to free channel from the dma_terminate_all()
callback. This callback terminates submitted descs, that's it.

https://elixir.bootlin.com/linux/v5.16-rc5/source/include/linux/dmaengine.h#L1105

https://elixir.bootlin.com/linux/v5.16-rc5/source/drivers/i2c/busses/i2c-tegra.c#L962