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/extcon/extcon-max3355.c | 140 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) create mode 100644 drivers/extcon/extcon-max3355.c (limited to 'drivers/extcon/extcon-max3355.c') diff --git a/drivers/extcon/extcon-max3355.c b/drivers/extcon/extcon-max3355.c new file mode 100644 index 000000000..d687d178a --- /dev/null +++ b/drivers/extcon/extcon-max3355.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Maxim Integrated MAX3355 USB OTG chip extcon driver + * + * Copyright (C) 2014-2015 Cogent Embedded, Inc. + * Author: Sergei Shtylyov + */ + +#include +#include +#include +#include +#include + +struct max3355_data { + struct extcon_dev *edev; + struct gpio_desc *id_gpiod; + struct gpio_desc *shdn_gpiod; +}; + +static const unsigned int max3355_cable[] = { + EXTCON_USB, + EXTCON_USB_HOST, + EXTCON_NONE, +}; + +static irqreturn_t max3355_id_irq(int irq, void *dev_id) +{ + struct max3355_data *data = dev_id; + int id = gpiod_get_value_cansleep(data->id_gpiod); + + if (id) { + /* + * ID = 1 means USB HOST cable detached. + * As we don't have event for USB peripheral cable attached, + * we simulate USB peripheral attach here. + */ + extcon_set_state_sync(data->edev, EXTCON_USB_HOST, false); + extcon_set_state_sync(data->edev, EXTCON_USB, true); + } else { + /* + * ID = 0 means USB HOST cable attached. + * As we don't have event for USB peripheral cable detached, + * we simulate USB peripheral detach here. + */ + extcon_set_state_sync(data->edev, EXTCON_USB, false); + extcon_set_state_sync(data->edev, EXTCON_USB_HOST, true); + } + + return IRQ_HANDLED; +} + +static int max3355_probe(struct platform_device *pdev) +{ + struct max3355_data *data; + struct gpio_desc *gpiod; + int irq, err; + + data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN); + if (IS_ERR(gpiod)) { + dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n"); + return PTR_ERR(gpiod); + } + data->id_gpiod = gpiod; + + gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH); + if (IS_ERR(gpiod)) { + dev_err(&pdev->dev, "failed to get SHDN# GPIO\n"); + return PTR_ERR(gpiod); + } + data->shdn_gpiod = gpiod; + + data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable); + if (IS_ERR(data->edev)) { + dev_err(&pdev->dev, "failed to allocate extcon device\n"); + return PTR_ERR(data->edev); + } + + err = devm_extcon_dev_register(&pdev->dev, data->edev); + if (err < 0) { + dev_err(&pdev->dev, "failed to register extcon device\n"); + return err; + } + + irq = gpiod_to_irq(data->id_gpiod); + if (irq < 0) { + dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n"); + return irq; + } + + err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq, + IRQF_ONESHOT | IRQF_NO_SUSPEND | + IRQF_TRIGGER_RISING | + IRQF_TRIGGER_FALLING, + pdev->name, data); + if (err < 0) { + dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n"); + return err; + } + + platform_set_drvdata(pdev, data); + + /* Perform initial detection */ + max3355_id_irq(irq, data); + + return 0; +} + +static void max3355_remove(struct platform_device *pdev) +{ + struct max3355_data *data = platform_get_drvdata(pdev); + + gpiod_set_value_cansleep(data->shdn_gpiod, 0); +} + +static const struct of_device_id max3355_match_table[] = { + { .compatible = "maxim,max3355", }, + { } +}; +MODULE_DEVICE_TABLE(of, max3355_match_table); + +static struct platform_driver max3355_driver = { + .probe = max3355_probe, + .remove = max3355_remove, + .driver = { + .name = "extcon-max3355", + .of_match_table = max3355_match_table, + }, +}; + +module_platform_driver(max3355_driver); + +MODULE_AUTHOR("Sergei Shtylyov "); +MODULE_DESCRIPTION("Maxim MAX3355 extcon driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1