On 20/05/15 04:57, Alexandre Courbot wrote:
[snip]
> There may still be a leak (that is not related to your patch) in the
> RX path though:
>
> dma_buf = dma_alloc_coherent(...);
> ret = dmaengine_slave_config(...);
> if (ret < 0) {
> ...
> goto scrub;
> }
>
> tup->rx_dma_buf_virt = dma_buf;
> tup->rx_dma_buf_phys = dma_phys;
>
> scrub:
> dma_release_channel(dma_chan);
> return ret;
>
> It seems that if dmaengine_slave_config() fails, then the result of
> dma_alloc_coherent() remains purely local to the function and is never
> freed. Or am I missing something again?
Yes, you are right here. Actually, this would be applicable to
both RX and TX paths because in the TX path the buffer would
not be unmapped. I will generated a separate patch for fix
this. How does the following look?
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index 3b63f103f0c9..cf0133ae762d 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -999,6 +999,12 @@ static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
dma_release_channel(dma_chan);
return -ENOMEM;
}
+ dma_sconfig.src_addr = tup->uport.mapbase;
+ dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconfig.src_maxburst = 4;
+ tup->rx_dma_chan = dma_chan;
+ tup->rx_dma_buf_virt = dma_buf;
+ tup->rx_dma_buf_phys = dma_phys;
} else {
dma_phys = dma_map_single(tup->uport.dev,
tup->uport.state->xmit.buf, UART_XMIT_SIZE,
@@ -1009,39 +1015,23 @@ static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
return -ENOMEM;
}
dma_buf = tup->uport.state->xmit.buf;
- }
-
- if (dma_to_memory) {
- dma_sconfig.src_addr = tup->uport.mapbase;
- dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
- dma_sconfig.src_maxburst = 4;
- } else {
dma_sconfig.dst_addr = tup->uport.mapbase;
dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
dma_sconfig.dst_maxburst = 16;
+ tup->tx_dma_chan = dma_chan;
+ tup->tx_dma_buf_virt = dma_buf;
+ tup->tx_dma_buf_phys = dma_phys;
}
ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
if (ret < 0) {
dev_err(tup->uport.dev,
"Dma slave config failed, err = %d\n", ret);
- goto scrub;
+ tegra_uart_dma_channel_free(tup, dma_to_memory);
+ return ret;
}
- if (dma_to_memory) {
- tup->rx_dma_chan = dma_chan;
- tup->rx_dma_buf_virt = dma_buf;
- tup->rx_dma_buf_phys = dma_phys;
- } else {
- tup->tx_dma_chan = dma_chan;
- tup->tx_dma_buf_virt = dma_buf;
- tup->tx_dma_buf_phys = dma_phys;
- }
return 0;
-
-scrub:
- tegra_uart_dma_channel_free(tup, dma_to_memory);
- return ret;
}
Cheers
Jon
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