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1788cf6a |
| 05-Apr-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: serial: switch from circ_buf to kfifo
Switch from struct circ_buf to proper kfifo. kfifo provides much better API, esp. when wrap-around of the buffer needs to be taken into account. Look at pl
tty: serial: switch from circ_buf to kfifo
Switch from struct circ_buf to proper kfifo. kfifo provides much better API, esp. when wrap-around of the buffer needs to be taken into account. Look at pl011_dma_tx_refill() or cpm_uart_tx_pump() changes for example.
Kfifo API can also fill in scatter-gather DMA structures, so it easier for that use case too. Look at lpuart_dma_tx() for example. Note that not all drivers can be converted to that (like atmel_serial), they handle DMA specially.
Note that usb-serial uses kfifo for TX for ages.
omap needed a bit more care as it needs to put a char into FIFO to start the DMA transfer when OMAP_DMA_TX_KICK is set. In that case, we have to do kfifo_dma_out_prepare twice: once to find out the tx_size (to find out if it is worths to do DMA at all -- size >= 4), the second time for the actual transfer.
All traces of circ_buf are removed from serial_core.h (and its struct uart_state).
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Al Cooper <alcooperx@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com> Cc: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: Maciej W. Rozycki <macro@orcam.me.uk> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Neil Armstrong <neil.armstrong@linaro.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Jerome Brunet <jbrunet@baylibre.com> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: Taichi Sugaya <sugaya.taichi@socionext.com> Cc: Takao Orito <orito.takao@socionext.com> Cc: Bjorn Andersson <andersson@kernel.org> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Pali Rohár <pali@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Alim Akhtar <alim.akhtar@samsung.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Orson Zhai <orsonzhai@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Patrice Chotard <patrice.chotard@foss.st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hammer Hsieh <hammerh0314@gmail.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@kernel.org> Cc: Michal Simek <michal.simek@amd.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/r/20240405060826.2521-13-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d19993c4 |
| 10-Nov-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
serial: cpm: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error h
serial: cpm: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove().
Trivially convert this driver from always returning zero in the remove callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231110152927.70601-12-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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34e04225 |
| 14-Sep-2023 |
Thomas Gleixner <tglx@linutronix.de> |
serial: cpm_uart: Use port lock wrappers
When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, a
serial: cpm_uart: Use port lock wrappers
When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure.
To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20230914183831.587273-24-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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dbae4258 |
| 03-Aug-2023 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
serial: cpm_uart: Remove cpm_uart/ subdirectory
cpm_uart/ subdirectory only has cpm_uart_core.c and cpm_uart.h now.
Move them up and remove cpm_uart/ directory while renaming cpm_uart_core.c as cpm
serial: cpm_uart: Remove cpm_uart/ subdirectory
cpm_uart/ subdirectory only has cpm_uart_core.c and cpm_uart.h now.
Move them up and remove cpm_uart/ directory while renaming cpm_uart_core.c as cpm_uart.c
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Link: https://lore.kernel.org/r/9b8b8f89fc386480030f5339abe307541ae436a6.1691068700.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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