linux/drivers/tty, branch v6.14

Merge tag 'tty-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2025-02-16T20:50:44Z

Pull serial driver fixes from Greg KH: "Here are some small serial driver fixes for some reported problems. Nothing major, just: - sc16is7xx irq check fix - 8250 fifo underflow fix - serial_port and 8250 iotype fixes Most of these have been in linux-next already, and all have passed 0-day testing" * tag 'tty-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: 8250: Fix fifo underflow on flush serial: 8250_pnp: Remove unneeded ->iotype assignment serial: 8250_platform: Remove unneeded ->iotype assignment serial: 8250_of: Remove unneeded ->iotype assignment serial: port: Make ->iotype validation global in __uart_read_properties() serial: port: Always update ->iotype in __uart_read_properties() serial: port: Assign ->iotype correctly when ->iobase is set serial: sc16is7xx: Fix IRQ number check behavior

serial: 8250: Fix fifo underflow on flush

2025-02-14T08:50:55Z

When flushing the serial port's buffer, uart_flush_buffer() calls kfifo_reset() but if there is an outstanding DMA transfer then the completion function will consume data from the kfifo via uart_xmit_advance(), underflowing and leading to ongoing DMA as the driver tries to transmit another 2^32 bytes. This is readily reproduced with serial-generic and amidi sending even short messages as closing the device on exit will wait for the fifo to drain and in the underflow case amidi hangs for 30 seconds on exit in tty_wait_until_sent(). A trace of that gives: kworker/1:1-84 [001] 51.769423: bprint: serial8250_tx_dma: tx_size=3 fifo_len=3 amidi-763 [001] 51.769460: bprint: uart_flush_buffer: resetting fifo irq/21-fe530000-76 [000] 51.769474: bprint: __dma_tx_complete: tx_size=3 irq/21-fe530000-76 [000] 51.769479: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294967293 irq/21-fe530000-76 [000] 51.781295: bprint: __dma_tx_complete: tx_size=4096 irq/21-fe530000-76 [000] 51.781301: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294963197 irq/21-fe530000-76 [000] 51.793131: bprint: __dma_tx_complete: tx_size=4096 irq/21-fe530000-76 [000] 51.793135: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294959101 irq/21-fe530000-76 [000] 51.804949: bprint: __dma_tx_complete: tx_size=4096 Since the port lock is held in when the kfifo is reset in uart_flush_buffer() and in __dma_tx_complete(), adding a flush_buffer hook to adjust the outstanding DMA byte count is sufficient to avoid the kfifo underflow. Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Cc: stable Signed-off-by: John Keeping Link: https://lore.kernel.org/r/20250208124148.1189191-1-jkeeping@inmusicbrands.com Signed-off-by: Greg Kroah-Hartman

fsnotify: use accessor to set FMODE_NONOTIFY_*

2025-02-07T09:27:26Z

The FMODE_NONOTIFY_* bits are a 2-bits mode. Open coding manipulation of those bits is risky. Use an accessor file_set_fsnotify_mode() to set the mode. Rename file_set_fsnotify_mode() => file_set_fsnotify_mode_from_watchers() to make way for the simple accessor name. Signed-off-by: Amir Goldstein Link: https://lore.kernel.org/r/20250203223205.861346-2-amir73il@gmail.com Signed-off-by: Christian Brauner

serial: 8250_pnp: Remove unneeded ->iotype assignment

2025-02-04T13:44:53Z

If ->iobase is set the default will be UPIO_PORT for ->iotype after the uart_read_and_validate_port_properties() call. Hence no need to assign that explicitly. Otherwise it will be UPIO_MEM. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250124161530.398361-7-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_platform: Remove unneeded ->iotype assignment

2025-02-04T13:44:52Z

If ->iobase is set the default will be UPIO_PORT for ->iotype after the uart_read_and_validate_port_properties() call. Hence no need to assign that explicitly. Otherwise it will be UPIO_MEM. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250124161530.398361-6-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_of: Remove unneeded ->iotype assignment

2025-02-04T13:44:50Z

If ->iobase is set the default will be UPIO_PORT for ->iotype after the uart_read_and_validate_port_properties() call. Hence no need to assign that explicitly. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250124161530.398361-5-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: port: Make ->iotype validation global in __uart_read_properties()

2025-02-04T13:44:44Z

In order to make code robust against potential changes in the future move ->iotype validation outside of switch in __uart_read_properties(). If any code will be added in between that might leave the ->iotype value unknown the validation catches this up. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250124161530.398361-4-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: port: Always update ->iotype in __uart_read_properties()

2025-02-04T13:44:41Z

The documentation of the __uart_read_properties() states that ->iotype member is always altered after the function call, but the code doesn't do that in the case when use_defaults == false and the value of reg-io-width is unsupported. Make sure the code follows the documentation. Note, the current users of the uart_read_and_validate_port_properties() will fail and the change doesn't affect their behaviour, neither users of uart_read_port_properties() will be affected since the alteration happens there even in the current code flow. Fixes: e894b6005dce ("serial: port: Introduce a common helper to read properties") Cc: stable Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250124161530.398361-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: port: Assign ->iotype correctly when ->iobase is set

2025-02-04T13:44:35Z

Currently the ->iotype is always assigned to the UPIO_MEM when the respective property is not found. However, this will not support the cases when user wants to have UPIO_PORT to be set or preserved. Support this scenario by checking ->iobase value and default the ->iotype respectively. Fixes: 1117a6fdc7c1 ("serial: 8250_of: Switch to use uart_read_port_properties()") Fixes: e894b6005dce ("serial: port: Introduce a common helper to read properties") Cc: stable Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250124161530.398361-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: sc16is7xx: Fix IRQ number check behavior

2025-02-04T13:42:42Z

The logical meaning of the previous version is wrong due to a typo. If the IRQ equals 0, no interrupt pin is available and polling mode shall be used. Additionally, this fix adds a check for IRQ < 0 to increase robustness, because documentation still says that negative IRQ values cannot be absolutely ruled-out. Fixes: 104c1b9dde9d ("serial: sc16is7xx: Add polling mode if no IRQ pin is available") Signed-off-by: Andre Werner Reviewed-by: Jiri Slaby Reviewed-by: Andy Shevchenko Reviewed-by: Maarten Brock Reviewed-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20250121071819.1346672-1-andre.werner@systec-electronic.com Signed-off-by: Greg Kroah-Hartman