From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- drivers/input/misc/pcspkr.c | 134 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 drivers/input/misc/pcspkr.c (limited to 'drivers/input/misc/pcspkr.c') diff --git a/drivers/input/misc/pcspkr.c b/drivers/input/misc/pcspkr.c new file mode 100644 index 000000000..046780840 --- /dev/null +++ b/drivers/input/misc/pcspkr.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PC Speaker beeper driver for Linux + * + * Copyright (c) 2002 Vojtech Pavlik + * Copyright (c) 1992 Orest Zborowski + */ + + +#include +#include +#include +#include +#include +#include +#include + +MODULE_AUTHOR("Vojtech Pavlik "); +MODULE_DESCRIPTION("PC Speaker beeper driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:pcspkr"); + +static int pcspkr_event(struct input_dev *dev, unsigned int type, + unsigned int code, int value) +{ + unsigned int count = 0; + unsigned long flags; + + if (type != EV_SND) + return -EINVAL; + + switch (code) { + case SND_BELL: + if (value) + value = 1000; + break; + case SND_TONE: + break; + default: + return -EINVAL; + } + + if (value > 20 && value < 32767) + count = PIT_TICK_RATE / value; + + raw_spin_lock_irqsave(&i8253_lock, flags); + + if (count) { + /* set command for counter 2, 2 byte write */ + outb_p(0xB6, 0x43); + /* select desired HZ */ + outb_p(count & 0xff, 0x42); + outb((count >> 8) & 0xff, 0x42); + /* enable counter 2 */ + outb_p(inb_p(0x61) | 3, 0x61); + } else { + /* disable counter 2 */ + outb(inb_p(0x61) & 0xFC, 0x61); + } + + raw_spin_unlock_irqrestore(&i8253_lock, flags); + + return 0; +} + +static int pcspkr_probe(struct platform_device *dev) +{ + struct input_dev *pcspkr_dev; + int err; + + pcspkr_dev = input_allocate_device(); + if (!pcspkr_dev) + return -ENOMEM; + + pcspkr_dev->name = "PC Speaker"; + pcspkr_dev->phys = "isa0061/input0"; + pcspkr_dev->id.bustype = BUS_ISA; + pcspkr_dev->id.vendor = 0x001f; + pcspkr_dev->id.product = 0x0001; + pcspkr_dev->id.version = 0x0100; + pcspkr_dev->dev.parent = &dev->dev; + + pcspkr_dev->evbit[0] = BIT_MASK(EV_SND); + pcspkr_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE); + pcspkr_dev->event = pcspkr_event; + + err = input_register_device(pcspkr_dev); + if (err) { + input_free_device(pcspkr_dev); + return err; + } + + platform_set_drvdata(dev, pcspkr_dev); + + return 0; +} + +static void pcspkr_remove(struct platform_device *dev) +{ + struct input_dev *pcspkr_dev = platform_get_drvdata(dev); + + input_unregister_device(pcspkr_dev); + /* turn off the speaker */ + pcspkr_event(NULL, EV_SND, SND_BELL, 0); +} + +static int pcspkr_suspend(struct device *dev) +{ + pcspkr_event(NULL, EV_SND, SND_BELL, 0); + + return 0; +} + +static void pcspkr_shutdown(struct platform_device *dev) +{ + /* turn off the speaker */ + pcspkr_event(NULL, EV_SND, SND_BELL, 0); +} + +static const struct dev_pm_ops pcspkr_pm_ops = { + .suspend = pcspkr_suspend, +}; + +static struct platform_driver pcspkr_platform_driver = { + .driver = { + .name = "pcspkr", + .pm = &pcspkr_pm_ops, + }, + .probe = pcspkr_probe, + .remove = pcspkr_remove, + .shutdown = pcspkr_shutdown, +}; +module_platform_driver(pcspkr_platform_driver); + -- cgit v1.3.1