kernel/linux.git/drivers/tty/serial/8250, branch v6.13.6

serial: 8250: Fix fifo underflow on flush

2025-02-21T13:11:06+00:00

commit 9e512eaaf8f4008c44ede3dfc0fbc9d9c5118583 upstream. 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

8250: microchip: pci1xxxx: Add workaround for RTS bit toggle

2025-02-21T13:10:56+00:00

[ Upstream commit e95cb63e57381f00d9274533ea7fd0ac3bf4e5b0 ] In the B0 revision, the RTS pin remains high due to incorrect hardware mapping. To address this issue, enable auto-direction control with the RTS bit in ADCL_CFG_REG. This configuration ensures that the RTS pin goes low when the terminal is opened and high when the terminal is closed. Additionally, we reset the step counter for Rx and Tx engines by writing into FRAC_DIV_CFG_REG. Signed-off-by: Rengarajan S Link: https://lore.kernel.org/r/20241218094017.18290-1-rengarajan.s@microchip.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_pci: Share WCH IDs with parport_serial driver

2025-02-21T13:10:55+00:00

[ Upstream commit 535a07698b8b3e6f305673102d297262cae2360a ] parport_serial driver uses subset of WCH IDs that are present in 8250_pci. Share them via pci_ids.h and switch parport_serial to use defined constants. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20241204031114.1029882-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_pci: Resolve WCH vendor ID ambiguity

2025-02-21T13:10:55+00:00

[ Upstream commit 16076ca3a1565491bcb28689e555d569a39391c7 ] There are two sites of the same brand: wch.cn and wch-ic.com. They are property of the same company, but it appears that they managed to get two different PCI vendor IDs. Rename them accordingly using standard pattern, i.e. PCI_VENDOR_ID_... While at it, move to PCI_VDEVICE() in the ID tables. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20241204031114.1029882-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250: Adjust the timeout for FIFO mode

2025-02-08T09:02:06+00:00

[ Upstream commit d91f98be26510f5f81ec66425bb0306d1ccd571a ] After a console has written a record into UART_TX, it uses wait_for_xmitr() to wait until the data has been sent out before returning. However, wait_for_xmitr() will timeout after 10ms, regardless if the data has been transmitted or not. For single bytes, this timeout is sufficient even at very slow baud rates, such as 1200bps. However, when FIFO mode is used, there may be 64 bytes pushed into the FIFO at once. At a baud rate of 115200bps, the 10ms timeout is still sufficient. But when using lower baud rates (such as 57600bps), the timeout is _not_ sufficient. This causes longer lines to be cut off, resulting in lost and horribly misformatted output on the console. When using FIFO mode, take the number of bytes into account to determine an appropriate maximum timeout. Increasing the timeout does not affect performance since ideally the timeout never occurs. Fixes: 8f3631f0f6eb ("serial/8250: Use fifo in 8250 console driver") Signed-off-by: John Ogness Reviewed-by: Andy Shevchenko Reviewed-by: Wander Lairson Costa Reviewed-by: Petr Mladek Link: https://lore.kernel.org/r/20250107212702.169493-2-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

tty: serial: 8250: Fix another runtime PM usage counter underflow

2024-12-23T18:01:18+00:00

The commit f9b11229b79c ("serial: 8250: Fix PM usage_count for console handover") fixed one runtime PM usage counter balance problem that occurs because .dev is not set during univ8250 setup preventing call to pm_runtime_get_sync(). Later, univ8250_console_exit() will trigger the runtime PM usage counter underflow as .dev is already set at that time. Call pm_runtime_get_sync() to balance the RPM usage counter also in serial8250_register_8250_port() before trying to add the port. Reported-by: Borislav Petkov (AMD) Fixes: bedb404e91bb ("serial: 8250_port: Don't use power management for kernel console") Cc: stable Tested-by: Borislav Petkov (AMD) Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20241210170120.2231-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: serial: Work around warning backtrace in serial8250_set_defaults

2024-12-06T07:00:01+00:00

Commit 7c7e6c8924e7 ("tty: serial: handle HAS_IOPORT dependencies") triggers warning backtraces on a number of platforms which don't support IO ports. WARNING: CPU: 0 PID: 0 at drivers/tty/serial/8250/8250_port.c:470 serial8250_set_defaults+0x148/0x1d8 Unsupported UART type 0 The problem is seen because serial8250_set_defaults() is called for all members of the serial8250_ports[] array even if that array is not initialized. Work around the problem by only displaying the warning if the port type is not 0 (UPIO_PORT) or if iobase is set for the port. Fixes: 7c7e6c8924e7 ("tty: serial: handle HAS_IOPORT dependencies") Acked-by: Arnd Bergmann Cc: Niklas Schnelle Signed-off-by: Guenter Roeck Tested-by: Stafford Horne Link: https://lore.kernel.org/r/20241205143033.2695333-1-linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman

module: Convert symbol namespace to string literal

2024-12-02T19:34:44+00:00

Clean up the existing export namespace code along the same lines of commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo) to __section("foo")") and for the same reason, it is not desired for the namespace argument to be a macro expansion itself. Scripted using git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file; do awk -i inplace ' /^#define EXPORT_SYMBOL_NS/ { gsub(/__stringify$ns$/, "ns"); print; next; } /^#define MODULE_IMPORT_NS/ { gsub(/__stringify$ns$/, "ns"); print; next; } /MODULE_IMPORT_NS/ { $0 = gensub(/MODULE_IMPORT_NS$([^)]*)$/, "MODULE_IMPORT_NS(\"\\1\")", "g"); } /EXPORT_SYMBOL_NS/ { if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)$([^,]+),/) { if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)$/ && $0 !~ /(EXPORT_SYMBOL_NS[^(]*)/ && $0 !~ /^my/) { getline line; gsub(/[[:space:]]*\\$/, ""); gsub(/[[:space:]]/, "", line); $0 = $0 " " line; } $0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)$([^,]+), ([^)]+)$/, "\\1(\\2, \"\\3\")", "g"); } } { print }' $file; done Requested-by: Masahiro Yamada Signed-off-by: Peter Zijlstra (Intel) Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH Signed-off-by: Linus Torvalds

Merge tag 'tty-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2024-11-30T17:03:16+00:00

Pull tty / serial driver updates from Greg KH: "Here is a small set of tty and serial driver updates for 6.13-rc1. Nothing major at all this time, only some small changes: - few device tree binding updates - 8250_exar serial driver updates - imx serial driver updates - sprd_serial driver updates - other tiny serial driver updates, full details in the shortlog All of these have been in linux-next for a while with one reported issue, but that commit has now been reverted" * tag 'tty-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (37 commits) Revert "serial: sh-sci: Clean sci_ports[0] after at earlycon exit" serial: amba-pl011: fix build regression dt-bindings: serial: Add a new compatible string for ums9632 serial: sprd: Add support for sc9632 tty/serial/altera_uart: unwrap error log string tty/serial/altera_jtaguart: unwrap error log string serial: amba-pl011: Fix RX stall when DMA is used tty: ldsic: fix tty_ldisc_autoload sysctl's proc_handler serial: 8250_fintek: Add support for F81216E serial: sh-sci: Clean sci_ports[0] after at earlycon exit tty: atmel_serial: Fix typo retreives to retrieves tty: atmel_serial: Use devm_platform_ioremap_resource() serial: 8250: omap: Move pm_runtime_get_sync tty: serial: samsung: Add Exynos8895 compatible dt-bindings: serial: samsung: Add samsung,exynos8895-uart compatible serial: 8250_dw: Add Sophgo SG2044 quirk dt-bindings: serial: snps-dw-apb-uart: Add Sophgo SG2044 uarts dt-bindings: serial: snps,dw-apb-uart: merge duplicate compatible entry. altera_jtaguart: Use dev_err() to report error attaching IRQ altera_uart: Use dev_err() to report error attaching IRQ handler ...

Merge tag 'asm-generic-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2024-11-20T23:13:02+00:00

Pull asm-generic updates from Arnd Bergmann: "These are a number of unrelated cleanups, generally simplifying the architecture specific header files: - A series from Al Viro simplifies asm/vga.h, after it turns out that most of it can be generalized. - A series from Julian Vetter adds a common version of memcpy_{to,from}io() and memset_io() and changes most architectures to use that instead of their own implementation - A series from Niklas Schnelle concludes his work to make PC style inb()/outb() optional - Nicolas Pitre contributes improvements for the generic do_div() helper - Christoph Hellwig adds a generic version of page_to_phys() and phys_to_page(), replacing the slightly different architecture specific definitions. - Uwe Kleine-Koenig has a minor cleanup for ioctl definitions" * tag 'asm-generic-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (24 commits) empty include/asm-generic/vga.h sparc: get rid of asm/vga.h asm/vga.h: don't bother with scr_mem{cpy,move}v() unless we need to vt_buffer.h: get rid of dead code in default scr_...() instances tty: serial: export serial_8250_warn_need_ioport lib/iomem_copy: fix kerneldoc format style hexagon: simplify asm/io.h for !HAS_IOPORT loongarch: Use new fallback IO memcpy/memset csky: Use new fallback IO memcpy/memset arm64: Use new fallback IO memcpy/memset New implementation for IO memcpy and IO memset watchdog: Add HAS_IOPORT dependency for SBC8360 and SBC7240 __arch_xprod64(): make __always_inline when optimizing for performance ARM: div64: improve __arch_xprod_64() asm-generic/div64: optimize/simplify __div64_const32() lib/math/test_div64: add some edge cases relevant to __div64_const32() asm-generic: add an optional pfn_valid check to page_to_phys asm-generic: provide generic page_to_phys and phys_to_page implementations asm-generic/io.h: Remove I/O port accessors for HAS_IOPORT=n tty: serial: handle HAS_IOPORT dependencies ...