From: Andy Shevchenko andriy.shevchenko@linux.intel.com
stable inclusion from stable-v5.10.110 commit 659fe4d653a2d628a22d3b560e33b581e6b63625 bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 5318f70da7e82649d794fc27d8a127c22aa3566e ]
The pci_get_slot() increases its reference count, the caller must decrement the reference count by calling pci_dev_put().
Fixes: 9a1870ce812e ("serial: 8250: don't use slave_id of dma_slave_config") Depends-on: a13e19cf3dc1 ("serial: 8250_lpss: split LPSS driver to separate module") Reported-by: Qing Wang wangqing@vivo.com Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20220223151240.70248-1-andriy.shevchenko@linux.int... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yu Liao liaoyu15@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/tty/serial/8250/8250_lpss.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c index 4dee8a9e0c95..dfb730b7ea2a 100644 --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -121,8 +121,7 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port) { struct dw_dma_slave *param = &lpss->dma_param; struct pci_dev *pdev = to_pci_dev(port->dev); - unsigned int dma_devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0); - struct pci_dev *dma_dev = pci_get_slot(pdev->bus, dma_devfn); + struct pci_dev *dma_dev;
switch (pdev->device) { case PCI_DEVICE_ID_INTEL_BYT_UART1: @@ -141,6 +140,8 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port) return -EINVAL; }
+ dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0)); + param->dma_dev = &dma_dev->dev; param->m_master = 0; param->p_master = 1; @@ -156,11 +157,26 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port) return 0; }
+static void byt_serial_exit(struct lpss8250 *lpss) +{ + struct dw_dma_slave *param = &lpss->dma_param; + + /* Paired with pci_get_slot() in the byt_serial_setup() above */ + put_device(param->dma_dev); +} + static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port) { return 0; }
+static void ehl_serial_exit(struct lpss8250 *lpss) +{ + struct uart_8250_port *up = serial8250_get_port(lpss->data.line); + + up->dma = NULL; +} + #ifdef CONFIG_SERIAL_8250_DMA static const struct dw_dma_platform_data qrk_serial_dma_pdata = { .nr_channels = 2, @@ -335,8 +351,7 @@ static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id) return 0;
err_exit: - if (lpss->board->exit) - lpss->board->exit(lpss); + lpss->board->exit(lpss); pci_free_irq_vectors(pdev); return ret; } @@ -347,8 +362,7 @@ static void lpss8250_remove(struct pci_dev *pdev)
serial8250_unregister_port(lpss->data.line);
- if (lpss->board->exit) - lpss->board->exit(lpss); + lpss->board->exit(lpss); pci_free_irq_vectors(pdev); }
@@ -356,12 +370,14 @@ static const struct lpss8250_board byt_board = { .freq = 100000000, .base_baud = 2764800, .setup = byt_serial_setup, + .exit = byt_serial_exit, };
static const struct lpss8250_board ehl_board = { .freq = 200000000, .base_baud = 12500000, .setup = ehl_serial_setup, + .exit = ehl_serial_exit, };
static const struct lpss8250_board qrk_board = {