Commit 5318f70d authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Greg Kroah-Hartman
Browse files

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



The pci_get_slot() increases its reference count, the caller
must decrement the reference count by calling pci_dev_put().

Fixes: 9a1870ce ("serial: 8250: don't use slave_id of dma_slave_config")
Depends-on: a13e19cf ("serial: 8250_lpss: split LPSS driver to separate module")
Reported-by: default avatarQing Wang <wangqing@vivo.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220223151240.70248-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 67ec6dd0

drivers/tty/serial/8250/8250_lpss.c

+22 −6
Original line number Original line Diff line number Diff line
@@ -117,8 +117,7 @@ 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:
@@ -137,6 +136,8 @@ 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;
@@ -152,6 +153,14 @@ 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)

{

{

	struct uart_8250_dma *dma = &lpss->data.dma;

	struct uart_8250_dma *dma = &lpss->data.dma;
@@ -170,6 +179,13 @@ 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,
@@ -344,7 +360,6 @@ 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;
@@ -356,7 +371,6 @@ 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);

}

}
@@ -365,12 +379,14 @@ 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 = {