Searched hist:f58c252e30cf74f68b0054293adc03b5923b9f0e (Results 1 – 4 of 4) sorted by relevance
/linux/drivers/tty/serial/8250/ |
H A D | 8250_dma.c | diff f58c252e30cf74f68b0054293adc03b5923b9f0e Mon Mar 14 10:14:32 CET 2022 Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> serial: 8250: fix XOFF/XON sending when DMA is used
When 8250 UART is using DMA, x_char (XON/XOFF) is never sent to the wire. After this change, x_char is injected correctly.
Create uart_xchar_out() helper for sending the x_char out and accounting related to it. It seems that almost every driver does these same steps with x_char. Except for 8250, however, almost all currently lack .serial_out so they cannot immediately take advantage of this new helper.
The downside of this patch is that it might reintroduce the problems some devices faced with mixed DMA/non-DMA transfer which caused revert f967fc8f165f (Revert "serial: 8250_dma: don't bother DMA with small transfers"). However, the impact should be limited to cases with XON/XOFF (that didn't work with DMA capable devices to begin with so this problem is not very likely to cause a major issue, if any at all).
Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Reported-by: Gilles Buloz <gilles.buloz@kontron.com> Tested-by: Gilles Buloz <gilles.buloz@kontron.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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H A D | 8250_port.c | diff f58c252e30cf74f68b0054293adc03b5923b9f0e Mon Mar 14 10:14:32 CET 2022 Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> serial: 8250: fix XOFF/XON sending when DMA is used
When 8250 UART is using DMA, x_char (XON/XOFF) is never sent to the wire. After this change, x_char is injected correctly.
Create uart_xchar_out() helper for sending the x_char out and accounting related to it. It seems that almost every driver does these same steps with x_char. Except for 8250, however, almost all currently lack .serial_out so they cannot immediately take advantage of this new helper.
The downside of this patch is that it might reintroduce the problems some devices faced with mixed DMA/non-DMA transfer which caused revert f967fc8f165f (Revert "serial: 8250_dma: don't bother DMA with small transfers"). However, the impact should be limited to cases with XON/XOFF (that didn't work with DMA capable devices to begin with so this problem is not very likely to cause a major issue, if any at all).
Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Reported-by: Gilles Buloz <gilles.buloz@kontron.com> Tested-by: Gilles Buloz <gilles.buloz@kontron.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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/linux/include/linux/ |
H A D | serial_core.h | diff f58c252e30cf74f68b0054293adc03b5923b9f0e Mon Mar 14 10:14:32 CET 2022 Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> serial: 8250: fix XOFF/XON sending when DMA is used
When 8250 UART is using DMA, x_char (XON/XOFF) is never sent to the wire. After this change, x_char is injected correctly.
Create uart_xchar_out() helper for sending the x_char out and accounting related to it. It seems that almost every driver does these same steps with x_char. Except for 8250, however, almost all currently lack .serial_out so they cannot immediately take advantage of this new helper.
The downside of this patch is that it might reintroduce the problems some devices faced with mixed DMA/non-DMA transfer which caused revert f967fc8f165f (Revert "serial: 8250_dma: don't bother DMA with small transfers"). However, the impact should be limited to cases with XON/XOFF (that didn't work with DMA capable devices to begin with so this problem is not very likely to cause a major issue, if any at all).
Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Reported-by: Gilles Buloz <gilles.buloz@kontron.com> Tested-by: Gilles Buloz <gilles.buloz@kontron.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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/linux/drivers/tty/serial/ |
H A D | serial_core.c | diff f58c252e30cf74f68b0054293adc03b5923b9f0e Mon Mar 14 10:14:32 CET 2022 Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> serial: 8250: fix XOFF/XON sending when DMA is used
When 8250 UART is using DMA, x_char (XON/XOFF) is never sent to the wire. After this change, x_char is injected correctly.
Create uart_xchar_out() helper for sending the x_char out and accounting related to it. It seems that almost every driver does these same steps with x_char. Except for 8250, however, almost all currently lack .serial_out so they cannot immediately take advantage of this new helper.
The downside of this patch is that it might reintroduce the problems some devices faced with mixed DMA/non-DMA transfer which caused revert f967fc8f165f (Revert "serial: 8250_dma: don't bother DMA with small transfers"). However, the impact should be limited to cases with XON/XOFF (that didn't work with DMA capable devices to begin with so this problem is not very likely to cause a major issue, if any at all).
Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Reported-by: Gilles Buloz <gilles.buloz@kontron.com> Tested-by: Gilles Buloz <gilles.buloz@kontron.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220314091432.4288-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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