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serial: 8250_lpss: Balance reference count for PCI DMA device

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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: 9a1870ce81 ("serial: 8250: don't use slave_id of dma_slave_config")
Depends-on: a13e19cf3d ("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.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Andy Shevchenko
2022-02-23 17:12:40 +02:00
committed by Greg Kroah-Hartman
parent 0aebb3944a
commit 659fe4d653
1 changed files with 22 additions and 6 deletions
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24
drivers/tty/serial/8250/8250_lpss.c
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@@ -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 dw_dma_slave *param = &lpss->dma_param;
struct pci_dev *pdev = to_pci_dev(port->dev); 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;
struct pci_dev *dma_dev = pci_get_slot(pdev->bus, dma_devfn);
switch (pdev->device) { switch (pdev->device) {
case PCI_DEVICE_ID_INTEL_BYT_UART1: 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; return -EINVAL;
} }
dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
param->dma_dev = &dma_dev->dev; param->dma_dev = &dma_dev->dev;
param->m_master = 0; param->m_master = 0;
param->p_master = 1; param->p_master = 1;
@@ -156,11 +157,26 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
return 0; 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) static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
{ {
return 0; 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 #ifdef CONFIG_SERIAL_8250_DMA
static const struct dw_dma_platform_data qrk_serial_dma_pdata = { static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
.nr_channels = 2, .nr_channels = 2,
@@ -335,7 +351,6 @@ static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return 0; return 0;
err_exit: err_exit:
if (lpss->board->exit)
lpss->board->exit(lpss); lpss->board->exit(lpss);
pci_free_irq_vectors(pdev); pci_free_irq_vectors(pdev);
return ret; return ret;
@@ -347,7 +362,6 @@ static void lpss8250_remove(struct pci_dev *pdev)
serial8250_unregister_port(lpss->data.line); serial8250_unregister_port(lpss->data.line);
if (lpss->board->exit)
lpss->board->exit(lpss); lpss->board->exit(lpss);
pci_free_irq_vectors(pdev); pci_free_irq_vectors(pdev);
} }
@@ -356,12 +370,14 @@ static const struct lpss8250_board byt_board = {
.freq = 100000000, .freq = 100000000,
.base_baud = 2764800, .base_baud = 2764800,
.setup = byt_serial_setup, .setup = byt_serial_setup,
.exit = byt_serial_exit,
}; };
static const struct lpss8250_board ehl_board = { static const struct lpss8250_board ehl_board = {
.freq = 200000000, .freq = 200000000,
.base_baud = 12500000, .base_baud = 12500000,
.setup = ehl_serial_setup, .setup = ehl_serial_setup,
.exit = ehl_serial_exit,
}; };
static const struct lpss8250_board qrk_board = { static const struct lpss8250_board qrk_board = {