diff options
| author | Heikki Krogerus <heikki.krogerus@linux.intel.com> | 2013-01-16 16:08:16 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-16 19:36:10 +0400 |
| commit | f5836a55dee705d47a16c32139c02721763ff699 (patch) | |
| tree | ba4a16a75fd89f2655c922d92ae6a89c741c298b /drivers | |
| parent | 053fac36b1d9f76adde96a2f731965aaab3c632b (diff) | |
| download | linux-f5836a55dee705d47a16c32139c02721763ff699.tar.xz | |
serial: 8250_dw: Set maxburst size
The default burst is often 1 byte which is not very optimal.
The ideal burst size when using 16550A type port would be
1/2 of fifosize, but this does not work with all Designware
implementations. Setting it to 1/4 fifosize.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index bfdaf8b2680b..117bb8b03598 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -178,6 +178,7 @@ dw8250_acpi_walk_resource(struct acpi_resource *res, void *data) slave->direction = DMA_MEM_TO_DEV; slave->dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; slave->slave_id = fixed_dma->request_lines; + slave->dst_maxburst = port->tx_loadsz / 4; dma->tx_chan_id = fixed_dma->channels; dma->tx_param = &dma->tx_chan_id; @@ -189,6 +190,7 @@ dw8250_acpi_walk_resource(struct acpi_resource *res, void *data) slave->direction = DMA_DEV_TO_MEM; slave->src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; slave->slave_id = fixed_dma->request_lines; + slave->src_maxburst = p->fifosize / 4; dma->rx_chan_id = fixed_dma->channels; dma->rx_param = &dma->rx_chan_id; @@ -296,6 +298,8 @@ static int dw8250_probe(struct platform_device *pdev) uart.port.serial_in = dw8250_serial_in; uart.port.serial_out = dw8250_serial_out; + dw8250_setup_port(&uart); + if (pdev->dev.of_node) { err = dw8250_probe_of(&uart.port); if (err) @@ -308,8 +312,6 @@ static int dw8250_probe(struct platform_device *pdev) return -ENODEV; } - dw8250_setup_port(&uart); - data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; |