kernel/linux.git/include/linux/serial_8250.h, branch v6.6.132

Revert "8250: add support for ASIX devices with a FIFO bug"

2023-06-21T15:55:53+00:00

This reverts commit eb26dfe8aa7eeb5a5aa0b7574550125f8aa4c3b3. Commit eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO bug") merged on Jul 13, 2012 adds a quirk for PCI_VENDOR_ID_ASIX (0x9710). But that ID is the same as PCI_VENDOR_ID_NETMOS defined in 1f8b061050c7 ("[PATCH] Netmos parallel/serial/combo support") merged on Mar 28, 2005. In pci_serial_quirks array, the NetMos entry always takes precedence over the ASIX entry even since it was initially merged, code in that commit is always unreachable. In my tests, adding the FIFO workaround to pci_netmos_init() makes no difference, and the vendor driver also does not have such workaround. Given that the code was never used for over a decade, it's safe to revert it. Also, the real PCI_VENDOR_ID_ASIX should be 0x125b, which is used on their newer AX99100 PCIe serial controllers released on 2016. The FIFO workaround should not be intended for these newer controllers, and it was never implemented in vendor driver. Fixes: eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO bug") Cc: stable Signed-off-by: Jiaqing Zhao Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20230619155743.827859-1-jiaqing.zhao@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: RT288x/Au1xxx code away from core

2023-05-13T10:47:26+00:00

A non-trivial amount of RT288x/Au1xxx code is encapsulated into ifdeffery in 8250_port / 8250_early and some if UPIO_AU blocks. Create a separate file from them. Also handle errors properly in the cases where RT288x/Au1xxx code is not configured. It seems that 0x1000 mapsize is likely overkill but I've kept it the same as previously (the value was shrunk to that value in commit b2b13cdfd05e ("SERIAL 8250: Fixes for Alchemy UARTs.")). Seemingly, the driver only needs to access register at 0x28 for the divisor latch. The Kconfig side is a bit tricky. As SERIAL_8250_RT288X is bool it can only be =y. It is possible to have SERIAL_8250=m + SERIAL_8250_RT288X=y which required altering when 8250/ is included or the rt288x would not be built. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230511121029.13128-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Add dl_read/write, bugs and mapsize into plat_serial8250_port

2023-05-13T10:47:26+00:00

Add mapsize, bugs, and divisor latch read/write functions (->dl_read/write()) into plat_serial8250_port to carry the setup necessary for RT288x/Au1xxx devices over to uart port. Document the added members with kerneldoc style but do not enable kerneldoc yet as there are many fields which remain undocumented. While at it, convert .bugs in struct uart_8250_port to u16 to match it with the type used in struct plat_serial8250_port. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230511121029.13128-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Document uart_8250_port's ->dl_read/write()

2023-05-13T10:47:26+00:00

Add documentation for the struct uart_8250_port divisor latch function pointers. Documentation is in kernel doc format but don't enable kernel doc yet as many other fields remain undocumented. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230511121029.13128-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Change dl_read/write to handle value as u32

2023-05-13T10:47:26+00:00

Divisor latch read/write functions currently handle the value is int. As the value is related to HW context, u32 makes much more sense than a signed type. While at it, name the parameters in the callback signature. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230511121029.13128-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: Remove extern from func prototypes in headers

2023-03-17T14:00:40+00:00

Remove unnecessary externs from function prototypes in serial_8250.h and serial_core.h. Suggested-by: Jiri Slaby Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230309080923.11778-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Reorder fields in 'struct plat_serial8250_port'

2023-03-09T16:17:10+00:00

Group some variables based on their sizes to reduce hole and avoid padding. On x86_64, this shrinks the size of 'struct plat_serial8250_port' from 144 to 128 bytes. It saves a few bytes of memory. Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/f3cb1efe1454e0615840fd331ee335bc441589a9.1676665358.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman

serial: 8250: Toggle IER bits on only after irq has been set up

2022-09-22T14:30:14+00:00

Invoking TIOCVHANGUP on 8250_mid port on Ice Lake-D and then reopening the port triggers these faults during serial8250_do_startup(): DMAR: DRHD: handling fault status reg 3 DMAR: [DMA Write NO_PASID] Request device [00:1a.0] fault addr 0x0 [fault reason 0x05] PTE Write access is not set If the IRQ hasn't been set up yet, the UART will have zeroes in its MSI address/data registers. Disabling the IRQ at the interrupt controller won't stop the UART from performing a DMA write to the address programmed in its MSI address register (zero) when it wants to signal an interrupt. The UARTs (in Ice Lake-D) implement PCI 2.1 style MSI without masking capability, so there is no way to mask the interrupt at the source PCI function level, except disabling the MSI capability entirely, but that would cause it to fall back to INTx# assertion, and the PCI specification prohibits disabling the MSI capability as a way to mask a function's interrupt service request. The MSI address register is zeroed by the hangup as the irq is freed. The interrupt is signalled during serial8250_do_startup() performing a THRE test that temporarily toggles THRI in IER. The THRE test currently occurs before UART's irq (and MSI address) is properly set up. Refactor serial8250_do_startup() such that irq is set up before the THRE test. The current irq setup code is intermixed with the timer setup code. As THRE test must be performed prior to the timer setup, extract it into own function and call it only after the THRE test. The ->setup_timer() needs to be part of the struct uart_8250_ops in order to not create circular dependency between 8250 and 8250_base modules. Fixes: 40b36daad0ac ("[PATCH] 8250 UART backup timer") Reported-by: Lennert Buytenhek Tested-by: Lennert Buytenhek Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220922070005.2965-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35+00:00

There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: create lsr_save_mask

2022-06-27T12:44:20+00:00

Allow drivers to alter LSR save mask. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220624204210.11112-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman