serial: pch: Fix PCI device refcount leak in pch_request_dma()

As comment of pci_get_slot() says, it returns a pci_device with its
refcount increased. The caller must decrement the reference count by
calling pci_dev_put().

Since 'dma_dev' is only used to filter the channel in filter(), we can
call pci_dev_put() before exiting from pch_request_dma(). Add the
missing pci_dev_put() for the normal and error path.

Fixes: 3c6a483275 ("Serial: EG20T: add PCH_UART driver")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Link: https://lore.kernel.org/r/20221122114559.27692-1-wangxiongfeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Xiongfeng Wang 2022-11-22 19:45:59 +08:00 committed by Greg Kroah-Hartman
parent 22cf92bb39
commit 8be3a7bf77

View File

@ -694,6 +694,7 @@ static void pch_request_dma(struct uart_port *port)
if (!chan) {
dev_err(priv->port.dev, "%s:dma_request_channel FAILS(Tx)\n",
__func__);
pci_dev_put(dma_dev);
return;
}
priv->chan_tx = chan;
@ -710,6 +711,7 @@ static void pch_request_dma(struct uart_port *port)
__func__);
dma_release_channel(priv->chan_tx);
priv->chan_tx = NULL;
pci_dev_put(dma_dev);
return;
}
@ -717,6 +719,8 @@ static void pch_request_dma(struct uart_port *port)
priv->rx_buf_virt = dma_alloc_coherent(port->dev, port->fifosize,
&priv->rx_buf_dma, GFP_KERNEL);
priv->chan_rx = chan;
pci_dev_put(dma_dev);
}
static void pch_dma_rx_complete(void *arg)