greybus-dev February 2026

greybus-dev@lists.linaro.org

22 participants
41 discussions

[PATCH v1 0/2] staging: greybus: audio: small fixes

by Hardik Phalet

This series contains two small fixes for the Greybus audio manager: 1) Fix a NULL dereference in gb_audio_manager_get_module(). 2) Drop a stale TODO in the module release callback. Both are correctness / cleanup fixes with no functional change beyond preventing crashes. Thanks, Hardik

1 month

[PATCH v3 00/14] greybus: introduce CPC as transport layer

by Damien Riégel

Hi, This patchset brings support for Silicon Labs' CPC protocol as transport layer for Greybus. CPC stands for Co-Processor Communication and currently exists as a userspace daemon [1] that enables multiple applications on a coprocessor to share a single physical link to a Linux host, using a protocol loosely based on HDLC [2]. While the userspace implementations serves its purpose, it has some redundancies with Greybus that makes it not very suitable for kernel integration as-is, and so the protocol has been modified to better fit with Greybus. Even though kernel and userspace implementations share the same name, they are not the same protocol and are not compatible. The kernel integration with Greybus is intended to superseed the userspace implementation. CPC is introduced as a module that sits between Greybus and CPC Host Device Drivers implementations, like SDIO or SPI. This patchset includes SDIO as physical layer but the protocol is not final and might change, it's mostly there to showcase all the elements. +----------------------------------------------------+ | Greybus | +----------------------------------------------------+ /|\ | \|/ +----------------------------------------------------+ | CPC | +----------------------------------------------------+ /|\ /|\ /|\ | | | \|/ \|/ \|/ +----------+ +---------+ +-----------+ | SDIO | | SPI | | Others | +----------+ +---------+ +-----------+ CPC implements some of the features of Unipro that Greybus relies upon, like reliable transmission. CPC takes care of detecting transmission errors and retransmit frames if necessary, but that feature is not part of the RFC to keep it concise. There's also a flow-control feature, preventing sending messages to already full cports. In order to implement these features, a 4-byte header is prepended to Greybus messages, making the whole header 12 bytes (Greybus header is 8 bytes). This RFC starts by implementing a shim layer between physical bus drivers (like SDIO and SPI) and Greybus, and progressively add more elements to it to make it useful in its own right. Finally, an SDIO driver is added to enable the communication with a remote device. [1] https://github.com/SiliconLabs/cpc-daemon [2] https://en.wikipedia.org/wiki/High-Level_Data_Link_Control Changes in v3: - addressed Jerome's review comments, mostly for SDIO driver - rewrote cover letter and commit messages across the series Changes in v2: - addressed review comments and errors reported by kernel bot - for SDIO driver, remove padding between headers and payloads when aggregating packets together Damien Riégel (13): greybus: cpc: add minimal CPC Host Device infrastructure greybus: cpc: introduce CPC cport structure greybus: cpc: use socket buffers instead of gb_message in TX path greybus: cpc: pack cport ID in Greybus header greybus: cpc: switch RX path to socket buffers greybus: cpc: introduce CPC header structure greybus: cpc: account for CPC header size in RX and TX path greybus: cpc: add and validate sequence numbers greybus: cpc: acknowledge all incoming messages greybus: cpc: use holding queue instead of sending out immediately greybus: cpc: honour remote's RX window greybus: cpc: let host device drivers dequeue TX frames greybus: cpc: add private data pointer in CPC Host Device Gabriel Beaulieu (1): greybus: cpc: add CPC SDIO host driver MAINTAINERS | 6 + drivers/greybus/Kconfig | 2 + drivers/greybus/Makefile | 2 + drivers/greybus/cpc/Kconfig | 24 ++ drivers/greybus/cpc/Makefile | 9 + drivers/greybus/cpc/cpc.h | 75 ++++++ drivers/greybus/cpc/cport.c | 112 ++++++++ drivers/greybus/cpc/header.c | 136 ++++++++++ drivers/greybus/cpc/header.h | 52 ++++ drivers/greybus/cpc/host.c | 319 ++++++++++++++++++++++ drivers/greybus/cpc/host.h | 63 +++++ drivers/greybus/cpc/protocol.c | 170 ++++++++++++ drivers/greybus/cpc/sdio.c | 480 +++++++++++++++++++++++++++++++++ 13 files changed, 1450 insertions(+) create mode 100644 drivers/greybus/cpc/Kconfig create mode 100644 drivers/greybus/cpc/Makefile create mode 100644 drivers/greybus/cpc/cpc.h create mode 100644 drivers/greybus/cpc/cport.c create mode 100644 drivers/greybus/cpc/header.c create mode 100644 drivers/greybus/cpc/header.h create mode 100644 drivers/greybus/cpc/host.c create mode 100644 drivers/greybus/cpc/host.h create mode 100644 drivers/greybus/cpc/protocol.c create mode 100644 drivers/greybus/cpc/sdio.c -- 2.52.0

1 month

[PATCH] staging: greybus: document codec mutex usage

by Bartłomiej Konecki

Add comments describing lock and register_mutex in struct gbaudio_codec_info. The lock protects the codec runtime state and module/DAI lists, while register_mutex protects hardware registers. Improve readability and clarify locking semantics. Signed-off-by: Bartłomiej Konecki <bartekkonecki97(a)gmail.com> --- drivers/staging/greybus/audio_codec.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/staging/greybus/audio_codec.h b/drivers/staging/greybus/audio_codec.h index f3f7a7ec6be4..90dd3426d4a4 100644 --- a/drivers/staging/greybus/audio_codec.h +++ b/drivers/staging/greybus/audio_codec.h @@ -70,8 +70,9 @@ struct gbaudio_codec_info { struct list_head module_list; /* to maintain runtime stream params for each DAI */ struct list_head dai_list; - struct mutex lock; + struct mutex lock; /* protects codec state and module/DAI lists */ struct mutex register_mutex; + /* serializes access to codec hardware registers*/ }; struct gbaudio_widget { -- 2.47.3

1 month

[PATCH v3 1/4] staging: greybus: added comment to mutex declaration in fw-management.c

by Rachit Dhar

Added comment to mutex declaration, to resolve a checkpatch.pl check. Signed-off-by: Rachit Dhar <rchtdhr(a)gmail.com> --- drivers/staging/greybus/fw-management.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/greybus/fw-management.c b/drivers/staging/greybus/fw-management.c index 152949c23d65..07a0e6b63cf3 100644 --- a/drivers/staging/greybus/fw-management.c +++ b/drivers/staging/greybus/fw-management.c @@ -28,7 +28,7 @@ struct fw_mgmt { /* Common id-map for interface and backend firmware requests */ struct ida id_map; - struct mutex mutex; + struct mutex mutex; /* protects fw_mgmt->disabled, and serializes ioctl */ struct completion completion; struct cdev cdev; struct device *class_device; -- 2.43.0

1 month, 1 week

PATCH 1/1: greybus/usb: handle unspecified lengths in hub_control

by Jose A. Perez de Azpillaga

From 1e099b581fe475905509b9d600015ea2500b8cf8 Mon Sep 17 00:00:00 2001 From: "Jose A. Perez de Azpillaga" <azpijr(a)gmail.com> Date: Wed, 11 Feb 2026 22:54:40 +0100 Subject: [PATCH] greybus/usb: handle unspecified lengths in hub_control Fixes the FIXME in hub_control where response length was not handled correctly. Signed-off-by: Jose A. Perez de Azpillaga <azpijr(a)gmail.com> --- drivers/staging/greybus/usb.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/staging/greybus/usb.c b/drivers/staging/greybus/usb.c index 475f24f20cd4..f5f5a4863ddc 100644 --- a/drivers/staging/greybus/usb.c +++ b/drivers/staging/greybus/usb.c @@ -105,8 +105,10 @@ static int hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex, size_t response_size; int ret; - /* FIXME: handle unspecified lengths */ - response_size = sizeof(*response) + wLength; + /* Calculate expected response size */ + response_size = sizeof(*response); + if (wLength) + response_size += wLength; operation = gb_operation_create(dev->connection, GB_USB_TYPE_HUB_CONTROL, @@ -127,9 +129,13 @@ static int hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex, goto out; if (wLength) { - /* Greybus core has verified response size */ - response = operation->response->payload; - memcpy(buf, response->buf, wLength); + size_t actual_size = operation->response->payload_size - sizeof(*response); + size_t copy_size = min(wLength, actual_size); + + if (copy_size) { + response = operation->response->payload; + memcpy(buf, response->buf, copy_size); + } } out: gb_operation_put(operation); -- 2.51.0

1 month, 1 week

[PATCH v3] [PATCH v3] staging: greybus: gbphy: Replace sprintf() with sysfs_emit()

by Neel Bullywon

Replace sprintf() with sysfs_emit() in the protocol_id_show() sysfs attribute function. This code is safe as-is, but replace sprintf() with sysfs_emit() because we are trying to get rid of calls to sprintf() as part of kernel hardening; sysfs_emit() is more appropriate in this context. Signed-off-by: Neel Bullywon <neelb2403(a)gmail.com> --- This was compile-tested only (no VM/hardware used) Changes in v2: - Subject: change to imperative "Replace" (was "Replaced"). - Wording and line breaks adjusted in the commit body for clarity. Changes in v3: - Clarify what "safe" means (buffer is PAGE_SIZE) per Dan Carpenter's suggestion. - Reflow lines to avoid awkward breaks. --- drivers/staging/greybus/gbphy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/greybus/gbphy.c b/drivers/staging/greybus/gbphy.c index 60cf09a302a7..55f132b09cee 100644 --- a/drivers/staging/greybus/gbphy.c +++ b/drivers/staging/greybus/gbphy.c @@ -31,7 +31,7 @@ static ssize_t protocol_id_show(struct device *dev, { struct gbphy_device *gbphy_dev = to_gbphy_dev(dev); - return sprintf(buf, "0x%02x\n", gbphy_dev->cport_desc->protocol_id); + return sysfs_emit(buf, "0x%02x\n", gbphy_dev->cport_desc->protocol_id); } static DEVICE_ATTR_RO(protocol_id); base-commit: de0674d9bc69699c497477d45172493393ae9007 -- 2.44.0

1 month, 2 weeks

[PATCH] staging: greybus: uart: migrated from IDR to XArray API

by Neel Bullywon

Replaced the IDR API with the XArray API for managing TTY minor numbers. This addresses the checkpatch warning about DEFINE_IDR being deprecated. Following changes include: - Replaced DEFINE_IDR with DEFINE_XARRAY_ALLOC - Replace idr_find with xa_load - Replace idr_alloc with xa_alloc - Replace idr_remove with xa_erase - Replace idr_destroy with xa_destroy - Updated the include to use xarray No core functional changes, just modernized the code to a new API. Signed-off-by: Neel Bullywon <neelb2403(a)gmail.com> --- drivers/staging/greybus/uart.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/staging/greybus/uart.c b/drivers/staging/greybus/uart.c index 5cece0a6606f..8bd6bf0a57a8 100644 --- a/drivers/staging/greybus/uart.c +++ b/drivers/staging/greybus/uart.c @@ -22,7 +22,7 @@ #include <linux/serial.h> #include <linux/tty_driver.h> #include <linux/tty_flip.h> -#include <linux/idr.h> +#include <linux/xarray.h> #include <linux/fs.h> #include <linux/kdev_t.h> #include <linux/kfifo.h> @@ -67,7 +67,7 @@ struct gb_tty { }; static struct tty_driver *gb_tty_driver; -static DEFINE_IDR(tty_minors); +static DEFINE_XARRAY_ALLOC(tty_minors); static DEFINE_MUTEX(table_lock); static int gb_uart_receive_data_handler(struct gb_operation *op) @@ -342,7 +342,7 @@ static struct gb_tty *get_gb_by_minor(unsigned int minor) struct gb_tty *gb_tty; mutex_lock(&table_lock); - gb_tty = idr_find(&tty_minors, minor); + gb_tty = xa_load(&tty_minors, minor); if (gb_tty) { mutex_lock(&gb_tty->mutex); if (gb_tty->disconnected) { @@ -362,7 +362,7 @@ static int alloc_minor(struct gb_tty *gb_tty) int minor; mutex_lock(&table_lock); - minor = idr_alloc(&tty_minors, gb_tty, 0, GB_NUM_MINORS, GFP_KERNEL); + minor = xa_alloc(&tty_minors, &minor, gb_tty, XA_LIMIT(0, GB_NUM_MINORS - 1), GFP_KERNEL); mutex_unlock(&table_lock); if (minor >= 0) gb_tty->minor = minor; @@ -375,7 +375,7 @@ static void release_minor(struct gb_tty *gb_tty) gb_tty->minor = 0; /* Maybe should use an invalid value instead */ mutex_lock(&table_lock); - idr_remove(&tty_minors, minor); + xa_erase(&tty_minors, minor); mutex_unlock(&table_lock); } @@ -984,7 +984,7 @@ static void gb_tty_exit(void) { tty_unregister_driver(gb_tty_driver); tty_driver_kref_put(gb_tty_driver); - idr_destroy(&tty_minors); + xa_destroy(&tty_minors); } static const struct gbphy_device_id gb_uart_id_table[] = { -- 2.44.0

1 month, 2 weeks

[PATCH v3 4/4] staging: greybus: resolved checkpatch checks for light.c

by Rachit Dhar

Added comment to mutex declarations, to resolve checkpatch.pl checks. Signed-off-by: Rachit Dhar <rchtdhr(a)gmail.com> --- drivers/staging/greybus/light.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c index e509fdc715db..1f2faa6d545d 100644 --- a/drivers/staging/greybus/light.c +++ b/drivers/staging/greybus/light.c @@ -37,7 +37,7 @@ struct gb_channel { bool releasing; bool strobe_state; bool active; - struct mutex lock; + struct mutex lock; /* protects gb_channel->active */ }; struct gb_light { @@ -59,7 +59,7 @@ struct gb_lights { struct gb_connection *connection; u8 lights_count; struct gb_light *lights; - struct mutex lights_lock; + struct mutex lights_lock; /* protects gb_lights->lights */ }; static void gb_lights_channel_free(struct gb_channel *channel); -- 2.43.0

1 month, 2 weeks

[PATCH v3 3/4] staging: greybus: resolved checkpatch checks for raw.c

by Rachit Dhar

Added comment to mutex declaration, to resolve checkpatch.pl check. Signed-off-by: Rachit Dhar <rchtdhr(a)gmail.com> --- drivers/staging/greybus/raw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/greybus/raw.c b/drivers/staging/greybus/raw.c index 71de6776739c..4f217f20f1c0 100644 --- a/drivers/staging/greybus/raw.c +++ b/drivers/staging/greybus/raw.c @@ -20,7 +20,7 @@ struct gb_raw { struct list_head list; int list_data; - struct mutex list_lock; + struct mutex list_lock; /* protects gb_raw->list and gb_raw->list_data */ dev_t dev; struct cdev cdev; struct device *device; -- 2.43.0

1 month, 2 weeks

[PATCH v3 0/4] staging: greybus: fixing checkpatch issues

by Rachit Dhar

This series fixes checkpatch.pl checks highlighted for files in greybus, for mutex declaration comments, and styling issues. Changes in v3: - Added cover letter detailing changes made in subsequent versions of patch-sets. - v2 patch-set was only emailed to maintainers. The email was forwarded to the lists, but this rendered the patch-set corrupted. v3 hopes to correct this. Changes in v2: - Split patch 1 into two individual patches 1/4 and 2/4 to keep logical changes separate. Rachit Dhar (4): staging: greybus: added comment to mutex declaration in fw-management.c staging: greybus: fixed styling issue in fw-management.c staging: greybus: resolved checkpatch checks for raw.c staging: greybus: resolved checkpatch checks for light.c drivers/staging/greybus/fw-management.c | 5 +++-- drivers/staging/greybus/light.c | 4 ++-- drivers/staging/greybus/raw.c | 2 +- 3 files changed, 6 insertions(+), 5 deletions(-) -- 2.43.0

1 month, 2 weeks

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greybus-dev February 2026