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/base/regmap/regmap-ac97.c | 90 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 drivers/base/regmap/regmap-ac97.c (limited to 'drivers/base/regmap/regmap-ac97.c') diff --git a/drivers/base/regmap/regmap-ac97.c b/drivers/base/regmap/regmap-ac97.c new file mode 100644 index 000000000..a561971c4 --- /dev/null +++ b/drivers/base/regmap/regmap-ac97.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Register map access API - AC'97 support +// +// Copyright 2013 Linaro Ltd. All rights reserved. + +#include +#include +#include +#include +#include +#include +#include + +#include + +bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg) +{ + switch (reg) { + case AC97_RESET: + case AC97_POWERDOWN: + case AC97_INT_PAGING: + case AC97_EXTENDED_ID: + case AC97_EXTENDED_STATUS: + case AC97_EXTENDED_MID: + case AC97_EXTENDED_MSTATUS: + case AC97_GPIO_STATUS: + case AC97_MISC_AFE: + case AC97_VENDOR_ID1: + case AC97_VENDOR_ID2: + case AC97_CODEC_CLASS_REV: + case AC97_PCI_SVID: + case AC97_PCI_SID: + case AC97_FUNC_SELECT: + case AC97_FUNC_INFO: + case AC97_SENSE_INFO: + return true; + default: + return false; + } +} +EXPORT_SYMBOL_GPL(regmap_ac97_default_volatile); + +static int regmap_ac97_reg_read(void *context, unsigned int reg, + unsigned int *val) +{ + struct snd_ac97 *ac97 = context; + + *val = ac97->bus->ops->read(ac97, reg); + + return 0; +} + +static int regmap_ac97_reg_write(void *context, unsigned int reg, + unsigned int val) +{ + struct snd_ac97 *ac97 = context; + + ac97->bus->ops->write(ac97, reg, val); + + return 0; +} + +static const struct regmap_bus ac97_regmap_bus = { + .reg_write = regmap_ac97_reg_write, + .reg_read = regmap_ac97_reg_read, +}; + +struct regmap *__regmap_init_ac97(struct snd_ac97 *ac97, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + return __regmap_init(&ac97->dev, &ac97_regmap_bus, ac97, config, + lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__regmap_init_ac97); + +struct regmap *__devm_regmap_init_ac97(struct snd_ac97 *ac97, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + return __devm_regmap_init(&ac97->dev, &ac97_regmap_bus, ac97, config, + lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__devm_regmap_init_ac97); + +MODULE_DESCRIPTION("Register map access API - AC'97 support"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1