Re: [PATCH] Input: serio - make write method mandatory
From: Nathan Chancellor <nathan@kernel.org>
Date: 2021-07-21 01:56:18
Also in:
linux-input, lkml
Subsystem:
hyper-v/azure core and drivers, input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Dmitry Torokhov, Linus Torvalds
On Sun, Mar 21, 2021 at 08:53:40PM -0700, Dmitry Torokhov wrote:
quoted hunk
Given that all serio drivers except one implement write() method let's make it mandatory to avoid testing for its presence whenever we attempt to use it. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> --- drivers/input/serio/ams_delta_serio.c | 6 ++++++ drivers/input/serio/serio.c | 5 +++++ include/linux/serio.h | 5 +---- 3 files changed, 12 insertions(+), 4 deletions(-)diff --git a/drivers/input/serio/ams_delta_serio.c b/drivers/input/serio/ams_delta_serio.c index 1c0be299f179..a1c314897951 100644 --- a/drivers/input/serio/ams_delta_serio.c +++ b/drivers/input/serio/ams_delta_serio.c@@ -89,6 +89,11 @@ static irqreturn_t ams_delta_serio_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } +static int ams_delta_serio_write(struct serio *serio, u8 data) +{ + return -EINVAL; +} + static int ams_delta_serio_open(struct serio *serio) { struct ams_delta_serio *priv = serio->port_data;@@ -157,6 +162,7 @@ static int ams_delta_serio_init(struct platform_device *pdev) priv->serio = serio; serio->id.type = SERIO_8042; + serio->write = ams_delta_serio_write; serio->open = ams_delta_serio_open; serio->close = ams_delta_serio_close; strlcpy(serio->name, "AMS DELTA keyboard adapter", sizeof(serio->name));diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c index 29f491082926..8d229a11bb6b 100644 --- a/drivers/input/serio/serio.c +++ b/drivers/input/serio/serio.c@@ -694,6 +694,11 @@ EXPORT_SYMBOL(serio_reconnect); */ void __serio_register_port(struct serio *serio, struct module *owner) { + if (!serio->write) { + pr_err("%s: refusing to register %s without write method\n", + __func__, serio->name); + return; + } serio_init_port(serio); serio_queue_event(serio, owner, SERIO_REGISTER_PORT); }diff --git a/include/linux/serio.h b/include/linux/serio.h index 6c27d413da92..075f1b8d76fa 100644 --- a/include/linux/serio.h +++ b/include/linux/serio.h@@ -121,10 +121,7 @@ void serio_unregister_driver(struct serio_driver *drv); static inline int serio_write(struct serio *serio, unsigned char data) { - if (serio->write) - return serio->write(serio, data); - else - return -1; + return serio->write(serio, data); } static inline void serio_drv_write_wakeup(struct serio *serio)-- 2.31.0.rc2.261.g7f71774620-goog -- Dmitry
This patch as commit 81c7c0a350bf ("Input: serio - make write method
mandatory") in -next breaks input for my Hyper-V VM, which prevents me
from logging in. I attempted to do something like the following (-1 or
-EINVAL) which should be equivalent but it does not resolve the issue.
Cheers,
Nathan
diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
index 1a7b72a9016d..d3eee2d4c327 100644
--- a/drivers/input/serio/hyperv-keyboard.c
+++ b/drivers/input/serio/hyperv-keyboard.c@@ -311,6 +311,11 @@ static void hv_kbd_stop(struct serio *serio) spin_unlock_irqrestore(&kbd_dev->lock, flags); } +static int hv_kbd_write(struct serio *serio, u8 data) +{ + return -1; +} + static int hv_kbd_probe(struct hv_device *hv_dev, const struct hv_vmbus_device_id *dev_id) {
@@ -341,6 +346,7 @@ static int hv_kbd_probe(struct hv_device *hv_dev, hv_serio->start = hv_kbd_start; hv_serio->stop = hv_kbd_stop; + hv_serio->write = hv_kbd_write; error = vmbus_open(hv_dev->channel, KBD_VSC_SEND_RING_BUFFER_SIZE,