[PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Francesco Dolcini]

From: Francesco Dolcini <francesco.dolcini@toradex.com>

receive_buf() is called from ttyport_receive_buf() that expects values
">= 0" from serdev_controller_receive_buf(), change its return type from
ssize_t to size_t.

Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
---
hello,
patch is based on current linux next.

It has an obvious problem, it touches files from multiple subsystem in a single
patch that is complicated to review and eventually merge, just splitting this
would however not work, it will break bisectability and the build.

I am looking for advise on the best way to move forward.

I see the following options:
 - keep it as it is
 - break it down with a patch with each subsystem, and squash before applying
   from a single (tty?) subsystem
 - go for a multi stage approach, defining a new callback, move to it and in
   the end remove the original one, likewise it was done for i2c lately

---
 drivers/bluetooth/btmtkuart.c              |  4 ++--
 drivers/bluetooth/btnxpuart.c              |  4 ++--
 drivers/bluetooth/hci_serdev.c             |  4 ++--
 drivers/gnss/core.c                        |  6 +++---
 drivers/gnss/serial.c                      |  4 ++--
 drivers/gnss/sirf.c                        |  6 +++---
 drivers/greybus/gb-beagleplay.c            |  6 +++---
 drivers/iio/chemical/pms7003.c             |  4 ++--
 drivers/iio/chemical/scd30_serial.c        |  4 ++--
 drivers/iio/chemical/sps30_serial.c        |  4 ++--
 drivers/iio/imu/bno055/bno055_ser_core.c   |  4 ++--
 drivers/mfd/rave-sp.c                      |  4 ++--
 drivers/net/ethernet/qualcomm/qca_uart.c   |  2 +-
 drivers/nfc/pn533/uart.c                   |  4 ++--
 drivers/nfc/s3fwrn5/uart.c                 |  4 ++--
 drivers/platform/chrome/cros_ec_uart.c     |  4 ++--
 drivers/platform/surface/aggregator/core.c |  4 ++--
 drivers/tty/serdev/serdev-ttyport.c        | 10 ++++------
 include/linux/gnss.h                       |  4 ++--
 include/linux/serdev.h                     |  8 ++++----
 sound/drivers/serial-generic.c             |  4 ++--
 21 files changed, 48 insertions(+), 50 deletions(-)

diff --git a/drivers/bluetooth/btmtkuart.c b/drivers/bluetooth/btmtkuart.c
index 3c84fcbda01a..e6bc4a73c9fc 100644
--- a/drivers/bluetooth/btmtkuart.c
+++ b/drivers/bluetooth/btmtkuart.c
@@ -383,8 +383,8 @@ static void btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
 	}
 }
 
-static ssize_t btmtkuart_receive_buf(struct serdev_device *serdev,
-				     const u8 *data, size_t count)
+static size_t btmtkuart_receive_buf(struct serdev_device *serdev,
+				    const u8 *data, size_t count)
 {
 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
 
diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
index 1d592ac413d1..056bef5b2919 100644
--- a/drivers/bluetooth/btnxpuart.c
+++ b/drivers/bluetooth/btnxpuart.c
@@ -1264,8 +1264,8 @@ static const struct h4_recv_pkt nxp_recv_pkts[] = {
 	{ NXP_RECV_FW_REQ_V3,   .recv = nxp_recv_fw_req_v3 },
 };
 
-static ssize_t btnxpuart_receive_buf(struct serdev_device *serdev,
-				     const u8 *data, size_t count)
+static size_t btnxpuart_receive_buf(struct serdev_device *serdev,
+				    const u8 *data, size_t count)
 {
 	struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
 
diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
index 39c8b567da3c..a3c3beb2806d 100644
--- a/drivers/bluetooth/hci_serdev.c
+++ b/drivers/bluetooth/hci_serdev.c
@@ -271,8 +271,8 @@ static void hci_uart_write_wakeup(struct serdev_device *serdev)
  *
  * Return: number of processed bytes
  */
-static ssize_t hci_uart_receive_buf(struct serdev_device *serdev,
-				    const u8 *data, size_t count)
+static size_t hci_uart_receive_buf(struct serdev_device *serdev,
+				   const u8 *data, size_t count)
 {
 	struct hci_uart *hu = serdev_device_get_drvdata(serdev);
 
diff --git a/drivers/gnss/core.c b/drivers/gnss/core.c
index 48f2ee0f78c4..9b8a0605ec76 100644
--- a/drivers/gnss/core.c
+++ b/drivers/gnss/core.c
@@ -317,10 +317,10 @@ EXPORT_SYMBOL_GPL(gnss_deregister_device);
  *
  * Must not be called for a closed device.
  */
-int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
-				size_t count)
+size_t gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
+		       size_t count)
 {
-	int ret;
+	size_t ret;
 
 	ret = kfifo_in(&gdev->read_fifo, buf, count);
 
diff --git a/drivers/gnss/serial.c b/drivers/gnss/serial.c
index baa956494e79..bf55aa2c1cf0 100644
--- a/drivers/gnss/serial.c
+++ b/drivers/gnss/serial.c
@@ -80,8 +80,8 @@ static const struct gnss_operations gnss_serial_gnss_ops = {
 	.write_raw	= gnss_serial_write_raw,
 };
 
-static ssize_t gnss_serial_receive_buf(struct serdev_device *serdev,
-				       const u8 *buf, size_t count)
+static size_t gnss_serial_receive_buf(struct serdev_device *serdev,
+				      const u8 *buf, size_t count)
 {
 	struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
 	struct gnss_device *gdev = gserial->gdev;
diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c
index 6801a8fb2040..2aae3c02156d 100644
--- a/drivers/gnss/sirf.c
+++ b/drivers/gnss/sirf.c
@@ -160,12 +160,12 @@ static const struct gnss_operations sirf_gnss_ops = {
 	.write_raw	= sirf_write_raw,
 };
 
-static ssize_t sirf_receive_buf(struct serdev_device *serdev,
-				const u8 *buf, size_t count)
+static size_t sirf_receive_buf(struct serdev_device *serdev,
+			       const u8 *buf, size_t count)
 {
 	struct sirf_data *data = serdev_device_get_drvdata(serdev);
 	struct gnss_device *gdev = data->gdev;
-	int ret = 0;
+	size_t ret = 0;
 
 	if (!data->wakeup && !data->active) {
 		data->active = true;
diff --git a/drivers/greybus/gb-beagleplay.c b/drivers/greybus/gb-beagleplay.c
index 2da37ff92cf1..26c95efe2fff 100644
--- a/drivers/greybus/gb-beagleplay.c
+++ b/drivers/greybus/gb-beagleplay.c
@@ -257,7 +257,7 @@ static void hdlc_rx_frame(struct gb_beagleplay *bg)
 	}
 }
 
-static ssize_t hdlc_rx(struct gb_beagleplay *bg, const u8 *data, size_t count)
+static size_t hdlc_rx(struct gb_beagleplay *bg, const u8 *data, size_t count)
 {
 	size_t i;
 	u8 c;
@@ -317,8 +317,8 @@ static void hdlc_deinit(struct gb_beagleplay *bg)
 	flush_work(&bg->tx_work);
 }
 
-static ssize_t gb_tty_receive(struct serdev_device *sd, const u8 *data,
-			      size_t count)
+static size_t gb_tty_receive(struct serdev_device *sd, const u8 *data,
+			     size_t count)
 {
 	struct gb_beagleplay *bg = serdev_device_get_drvdata(sd);
 
diff --git a/drivers/iio/chemical/pms7003.c b/drivers/iio/chemical/pms7003.c
index b5cf15a515d2..43025866d5b7 100644
--- a/drivers/iio/chemical/pms7003.c
+++ b/drivers/iio/chemical/pms7003.c
@@ -211,8 +211,8 @@ static bool pms7003_frame_is_okay(struct pms7003_frame *frame)
 	return checksum == pms7003_calc_checksum(frame);
 }
 
-static ssize_t pms7003_receive_buf(struct serdev_device *serdev, const u8 *buf,
-				   size_t size)
+static size_t pms7003_receive_buf(struct serdev_device *serdev, const u8 *buf,
+				  size_t size)
 {
 	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
 	struct pms7003_state *state = iio_priv(indio_dev);
diff --git a/drivers/iio/chemical/scd30_serial.c b/drivers/iio/chemical/scd30_serial.c
index a47654591e55..2adb76dbb020 100644
--- a/drivers/iio/chemical/scd30_serial.c
+++ b/drivers/iio/chemical/scd30_serial.c
@@ -174,8 +174,8 @@ static int scd30_serdev_command(struct scd30_state *state, enum scd30_cmd cmd, u
 	return 0;
 }
 
-static ssize_t scd30_serdev_receive_buf(struct serdev_device *serdev,
-					const u8 *buf, size_t size)
+static size_t scd30_serdev_receive_buf(struct serdev_device *serdev,
+				       const u8 *buf, size_t size)
 {
 	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
 	struct scd30_serdev_priv *priv;
diff --git a/drivers/iio/chemical/sps30_serial.c b/drivers/iio/chemical/sps30_serial.c
index 3afa89f8acc3..a6dfbe28c914 100644
--- a/drivers/iio/chemical/sps30_serial.c
+++ b/drivers/iio/chemical/sps30_serial.c
@@ -210,8 +210,8 @@ static int sps30_serial_command(struct sps30_state *state, unsigned char cmd,
 	return rsp_size;
 }
 
-static ssize_t sps30_serial_receive_buf(struct serdev_device *serdev,
-					const u8 *buf, size_t size)
+static size_t sps30_serial_receive_buf(struct serdev_device *serdev,
+				       const u8 *buf, size_t size)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev);
 	struct sps30_serial_priv *priv;
diff --git a/drivers/iio/imu/bno055/bno055_ser_core.c b/drivers/iio/imu/bno055/bno055_ser_core.c
index 5677bdf4f846..694ff14a3aa2 100644
--- a/drivers/iio/imu/bno055/bno055_ser_core.c
+++ b/drivers/iio/imu/bno055/bno055_ser_core.c
@@ -378,8 +378,8 @@ static void bno055_ser_handle_rx(struct bno055_ser_priv *priv, int status)
  * Also, we assume to RX one pkt per time (i.e. the HW doesn't send anything
  * unless we require to AND we don't queue more than one request per time).
  */
-static ssize_t bno055_ser_receive_buf(struct serdev_device *serdev,
-				      const u8 *buf, size_t size)
+static size_t bno055_ser_receive_buf(struct serdev_device *serdev,
+				     const u8 *buf, size_t size)
 {
 	int status;
 	struct bno055_ser_priv *priv = serdev_device_get_drvdata(serdev);
diff --git a/drivers/mfd/rave-sp.c b/drivers/mfd/rave-sp.c
index b1229bb143ee..f517e59e1c01 100644
--- a/drivers/mfd/rave-sp.c
+++ b/drivers/mfd/rave-sp.c
@@ -471,8 +471,8 @@ static void rave_sp_receive_frame(struct rave_sp *sp,
 		rave_sp_receive_reply(sp, data, length);
 }
 
-static ssize_t rave_sp_receive_buf(struct serdev_device *serdev,
-				   const u8 *buf, size_t size)
+static size_t rave_sp_receive_buf(struct serdev_device *serdev,
+				  const u8 *buf, size_t size)
 {
 	struct device *dev = &serdev->dev;
 	struct rave_sp *sp = dev_get_drvdata(dev);
diff --git a/drivers/net/ethernet/qualcomm/qca_uart.c b/drivers/net/ethernet/qualcomm/qca_uart.c
index 223321897b96..20f50bde82ac 100644
--- a/drivers/net/ethernet/qualcomm/qca_uart.c
+++ b/drivers/net/ethernet/qualcomm/qca_uart.c
@@ -58,7 +58,7 @@ struct qcauart {
 	unsigned char *tx_buffer;
 };
 
-static ssize_t
+static size_t
 qca_tty_receive(struct serdev_device *serdev, const u8 *data, size_t count)
 {
 	struct qcauart *qca = serdev_device_get_drvdata(serdev);
diff --git a/drivers/nfc/pn533/uart.c b/drivers/nfc/pn533/uart.c
index 2eb5978bd79e..cfbbe0713317 100644
--- a/drivers/nfc/pn533/uart.c
+++ b/drivers/nfc/pn533/uart.c
@@ -203,8 +203,8 @@ static int pn532_uart_rx_is_frame(struct sk_buff *skb)
 	return 0;
 }
 
-static ssize_t pn532_receive_buf(struct serdev_device *serdev,
-				 const u8 *data, size_t count)
+static size_t pn532_receive_buf(struct serdev_device *serdev,
+				const u8 *data, size_t count)
 {
 	struct pn532_uart_phy *dev = serdev_device_get_drvdata(serdev);
 	size_t i;
diff --git a/drivers/nfc/s3fwrn5/uart.c b/drivers/nfc/s3fwrn5/uart.c
index 456d3947116c..9c09c10c2a46 100644
--- a/drivers/nfc/s3fwrn5/uart.c
+++ b/drivers/nfc/s3fwrn5/uart.c
@@ -51,8 +51,8 @@ static const struct s3fwrn5_phy_ops uart_phy_ops = {
 	.write = s3fwrn82_uart_write,
 };
 
-static ssize_t s3fwrn82_uart_read(struct serdev_device *serdev,
-				  const u8 *data, size_t count)
+static size_t s3fwrn82_uart_read(struct serdev_device *serdev,
+				 const u8 *data, size_t count)
 {
 	struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);
 	size_t i;
diff --git a/drivers/platform/chrome/cros_ec_uart.c b/drivers/platform/chrome/cros_ec_uart.c
index 68d80559fddc..8ea867c2a01a 100644
--- a/drivers/platform/chrome/cros_ec_uart.c
+++ b/drivers/platform/chrome/cros_ec_uart.c
@@ -81,8 +81,8 @@ struct cros_ec_uart {
 	struct response_info response;
 };
 
-static ssize_t cros_ec_uart_rx_bytes(struct serdev_device *serdev,
-				     const u8 *data, size_t count)
+static size_t cros_ec_uart_rx_bytes(struct serdev_device *serdev,
+				    const u8 *data, size_t count)
 {
 	struct ec_host_response *host_response;
 	struct cros_ec_device *ec_dev = serdev_device_get_drvdata(serdev);
diff --git a/drivers/platform/surface/aggregator/core.c b/drivers/platform/surface/aggregator/core.c
index 9591a28bc38a..ba550eaa06fc 100644
--- a/drivers/platform/surface/aggregator/core.c
+++ b/drivers/platform/surface/aggregator/core.c
@@ -227,8 +227,8 @@ EXPORT_SYMBOL_GPL(ssam_client_bind);
 
 /* -- Glue layer (serdev_device -> ssam_controller). ------------------------ */
 
-static ssize_t ssam_receive_buf(struct serdev_device *dev, const u8 *buf,
-				size_t n)
+static size_t ssam_receive_buf(struct serdev_device *dev, const u8 *buf,
+			       size_t n)
 {
 	struct ssam_controller *ctrl;
 	int ret;
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index e94e090cf0a1..3d7ae7fa5018 100644
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -27,19 +27,17 @@ static size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp,
 {
 	struct serdev_controller *ctrl = port->client_data;
 	struct serport *serport = serdev_controller_get_drvdata(ctrl);
-	int ret;
+	size_t ret;
 
 	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
 		return 0;
 
 	ret = serdev_controller_receive_buf(ctrl, cp, count);
 
-	dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
-				"receive_buf returns %d (count = %zu)\n",
+	dev_WARN_ONCE(&ctrl->dev, ret > count,
+				"receive_buf returns %zu (count = %zu)\n",
 				ret, count);
-	if (ret < 0)
-		return 0;
-	else if (ret > count)
+	if (ret > count)
 		return count;
 
 	return ret;
diff --git a/include/linux/gnss.h b/include/linux/gnss.h
index 36968a0f33e8..9857c4029e65 100644
--- a/include/linux/gnss.h
+++ b/include/linux/gnss.h
@@ -60,8 +60,8 @@ void gnss_put_device(struct gnss_device *gdev);
 int gnss_register_device(struct gnss_device *gdev);
 void gnss_deregister_device(struct gnss_device *gdev);
 
-int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
-			size_t count);
+size_t gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
+		       size_t count);
 
 static inline void gnss_set_drvdata(struct gnss_device *gdev, void *data)
 {
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 3fab88ba265e..ff78efc1f60d 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -27,7 +27,7 @@ struct serdev_device;
  *			not sleep.
  */
 struct serdev_device_ops {
-	ssize_t (*receive_buf)(struct serdev_device *, const u8 *, size_t);
+	size_t (*receive_buf)(struct serdev_device *, const u8 *, size_t);
 	void (*write_wakeup)(struct serdev_device *);
 };
 
@@ -185,9 +185,9 @@ static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl
 	serdev->ops->write_wakeup(serdev);
 }
 
-static inline ssize_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
-						    const u8 *data,
-						    size_t count)
+static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
+						   const u8 *data,
+						   size_t count)
 {
 	struct serdev_device *serdev = ctrl->serdev;
 
diff --git a/sound/drivers/serial-generic.c b/sound/drivers/serial-generic.c
index d6e5aafd697c..36409a56c675 100644
--- a/sound/drivers/serial-generic.c
+++ b/sound/drivers/serial-generic.c
@@ -100,8 +100,8 @@ static void snd_serial_generic_write_wakeup(struct serdev_device *serdev)
 	snd_serial_generic_tx_wakeup(drvdata);
 }
 
-static ssize_t snd_serial_generic_receive_buf(struct serdev_device *serdev,
-					      const u8 *buf, size_t count)
+static size_t snd_serial_generic_receive_buf(struct serdev_device *serdev,
+					     const u8 *buf, size_t count)
 {
 	int ret;
 	struct snd_serial_generic *drvdata = serdev_device_get_drvdata(serdev);

base-commit: 11651f8cb2e88372d4ed523d909514dc9a613ea3
-- 
2.25.1

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Francesco Dolcini]

On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> From: Francesco Dolcini <francesco.dolcini@toradex.com>
> 
> receive_buf() is called from ttyport_receive_buf() that expects values
> ">= 0" from serdev_controller_receive_buf(), change its return type from
> ssize_t to size_t.
> 
> Suggested-by: Jiri Slaby <jirislaby@kernel.org>
> Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> ---
> hello,
> patch is based on current linux next.
> 
> It has an obvious problem, it touches files from multiple subsystem in a single
> patch that is complicated to review and eventually merge, just splitting this
> would however not work, it will break bisectability and the build.
> 
> I am looking for advise on the best way to move forward.
> 
> I see the following options:
>  - keep it as it is
>  - break it down with a patch with each subsystem, and squash before applying
>    from a single (tty?) subsystem
>  - go for a multi stage approach, defining a new callback, move to it and in
>    the end remove the original one, likewise it was done for i2c lately

whoops. I just noticed Greg applied commit 475fc6e2de6f ("tty: serdev:
convert to u8 and size_t") that touch the exact same files without much
of an issue.

Probably the "keep it as it is" is just the way to go.

> 
> ---
>  drivers/bluetooth/btmtkuart.c              |  4 ++--
>  drivers/bluetooth/btnxpuart.c              |  4 ++--
>  drivers/bluetooth/hci_serdev.c             |  4 ++--
>  drivers/gnss/core.c                        |  6 +++---
>  drivers/gnss/serial.c                      |  4 ++--
>  drivers/gnss/sirf.c                        |  6 +++---
>  drivers/greybus/gb-beagleplay.c            |  6 +++---
>  drivers/iio/chemical/pms7003.c             |  4 ++--
>  drivers/iio/chemical/scd30_serial.c        |  4 ++--
>  drivers/iio/chemical/sps30_serial.c        |  4 ++--
>  drivers/iio/imu/bno055/bno055_ser_core.c   |  4 ++--
>  drivers/mfd/rave-sp.c                      |  4 ++--
>  drivers/net/ethernet/qualcomm/qca_uart.c   |  2 +-
>  drivers/nfc/pn533/uart.c                   |  4 ++--
>  drivers/nfc/s3fwrn5/uart.c                 |  4 ++--
>  drivers/platform/chrome/cros_ec_uart.c     |  4 ++--
>  drivers/platform/surface/aggregator/core.c |  4 ++--
>  drivers/tty/serdev/serdev-ttyport.c        | 10 ++++------
>  include/linux/gnss.h                       |  4 ++--
>  include/linux/serdev.h                     |  8 ++++----
>  sound/drivers/serial-generic.c             |  4 ++--
>  21 files changed, 48 insertions(+), 50 deletions(-)

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Greg Kroah-Hartman]

On Thu, Dec 14, 2023 at 06:39:44PM +0100, Francesco Dolcini wrote:
> On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > 
> > receive_buf() is called from ttyport_receive_buf() that expects values
> > ">= 0" from serdev_controller_receive_buf(), change its return type from
> > ssize_t to size_t.
> > 
> > Suggested-by: Jiri Slaby <jirislaby@kernel.org>
> > Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
> > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > ---
> > hello,
> > patch is based on current linux next.
> > 
> > It has an obvious problem, it touches files from multiple subsystem in a single
> > patch that is complicated to review and eventually merge, just splitting this
> > would however not work, it will break bisectability and the build.
> > 
> > I am looking for advise on the best way to move forward.
> > 
> > I see the following options:
> >  - keep it as it is
> >  - break it down with a patch with each subsystem, and squash before applying
> >    from a single (tty?) subsystem
> >  - go for a multi stage approach, defining a new callback, move to it and in
> >    the end remove the original one, likewise it was done for i2c lately
> 
> whoops. I just noticed Greg applied commit 475fc6e2de6f ("tty: serdev:
> convert to u8 and size_t") that touch the exact same files without much
> of an issue.
> 
> Probably the "keep it as it is" is just the way to go.

Yeah, looks good to me, now queued up, thanks!

greg k-h

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Johan Hovold]

On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> From: Francesco Dolcini <francesco.dolcini@toradex.com>
> 
> receive_buf() is called from ttyport_receive_buf() that expects values
> ">= 0" from serdev_controller_receive_buf(), change its return type from
> ssize_t to size_t.
> 
> Suggested-by: Jiri Slaby <jirislaby@kernel.org>
> Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> ---
>  drivers/gnss/core.c                        |  6 +++---
>  drivers/gnss/serial.c                      |  4 ++--
>  drivers/gnss/sirf.c                        |  6 +++---

> diff --git a/drivers/gnss/core.c b/drivers/gnss/core.c
> index 48f2ee0f78c4..9b8a0605ec76 100644
> --- a/drivers/gnss/core.c
> +++ b/drivers/gnss/core.c
> @@ -317,10 +317,10 @@ EXPORT_SYMBOL_GPL(gnss_deregister_device);
>   *
>   * Must not be called for a closed device.
>   */
> -int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> -				size_t count)
> +size_t gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> +		       size_t count)
>  {
> -	int ret;
> +	size_t ret;
>  
>  	ret = kfifo_in(&gdev->read_fifo, buf, count);
>  

Why are you changing this function? This is part of the GNSS interface
and has nothing to do with the rest of this patch.

Greg, please drop this one again until this has been resolved.

Johan

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Francesco Dolcini]

Hello Johan,

On Fri, Dec 15, 2023 at 02:36:31PM +0100, Johan Hovold wrote:
> On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > 
> > receive_buf() is called from ttyport_receive_buf() that expects values
> > ">= 0" from serdev_controller_receive_buf(), change its return type from
> > ssize_t to size_t.
> > 
> > Suggested-by: Jiri Slaby <jirislaby@kernel.org>
> > Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
> > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > ---
> >  drivers/gnss/core.c                        |  6 +++---
> >  drivers/gnss/serial.c                      |  4 ++--
> >  drivers/gnss/sirf.c                        |  6 +++---
> 
> > diff --git a/drivers/gnss/core.c b/drivers/gnss/core.c
> > index 48f2ee0f78c4..9b8a0605ec76 100644
> > --- a/drivers/gnss/core.c
> > +++ b/drivers/gnss/core.c
> > @@ -317,10 +317,10 @@ EXPORT_SYMBOL_GPL(gnss_deregister_device);
> >   *
> >   * Must not be called for a closed device.
> >   */
> > -int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> > -				size_t count)
> > +size_t gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> > +		       size_t count)
> >  {
> > -	int ret;
> > +	size_t ret;
> >  
> >  	ret = kfifo_in(&gdev->read_fifo, buf, count);
> >  
> 
> Why are you changing this function? This is part of the GNSS interface
> and has nothing to do with the rest of this patch.

good point, thanks for looking into that.

from my understanding kfifo_in() already return an unsigned, both
__kfifo_in and __kfifo_in_r return unsigned.

With that said this is used by 3 drivers:

= drivers/gnss/sirf.c:
= drivers/gnss/serial.c:

The driver just use it into the actual receive_buf callback.

= drivers/gnss/usb.c

This driver does nothing with a negative return value (that is never the
less not possible), it just check that the whole buffer was inserted.

To me the change is correct, with that said probably this should have
been explicitly mentioned in the commit message or a separate
preparation patch.

Francesco

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Johan Hovold]

On Fri, Dec 15, 2023 at 02:55:59PM +0100, Francesco Dolcini wrote:
> On Fri, Dec 15, 2023 at 02:36:31PM +0100, Johan Hovold wrote:
> > On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> > > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > > 
> > > receive_buf() is called from ttyport_receive_buf() that expects values
> > > ">= 0" from serdev_controller_receive_buf(), change its return type from
> > > ssize_t to size_t.

> > > -int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> > > -				size_t count)
> > > +size_t gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> > > +		       size_t count)
> > >  {
> > > -	int ret;
> > > +	size_t ret;
> > >  
> > >  	ret = kfifo_in(&gdev->read_fifo, buf, count);
> > >  
> > 
> > Why are you changing this function? This is part of the GNSS interface
> > and has nothing to do with the rest of this patch.
> 
> good point, thanks for looking into that.
> 
> from my understanding kfifo_in() already return an unsigned, both
> __kfifo_in and __kfifo_in_r return unsigned.

Correct.

> With that said this is used by 3 drivers:
> 
> = drivers/gnss/sirf.c:
> = drivers/gnss/serial.c:
> 
> The driver just use it into the actual receive_buf callback.
> 
> = drivers/gnss/usb.c
> 
> This driver does nothing with a negative return value (that is never the
> less not possible), it just check that the whole buffer was inserted.

That driver also knows it will never be negative.

And you forgot about

	drivers/net/ethernet/intel/ice/ice_gnss.c

> To me the change is correct, with that said probably this should have
> been explicitly mentioned in the commit message or a separate
> preparation patch.

It's a separate change and should not be hidden away in a tree-wide
change that goes through a different maintainer.

Please drop this change from this patch and resubmit it separately to me
if you want and I'll review when I have the time.

And when doing tree-wide changes, please try to follow the style of the
driver you are changing (e.g. do not introduce inconsistencies by
changing to open parenthesis alignment of continuation lines in code
that do not use it).

Johan

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Francesco Dolcini]

Hello Johan, Greg

On Fri, Dec 15, 2023 at 05:18:52PM +0100, Johan Hovold wrote:
> On Fri, Dec 15, 2023 at 02:55:59PM +0100, Francesco Dolcini wrote:
> > To me the change is correct, with that said probably this should have
> > been explicitly mentioned in the commit message or a separate
> > preparation patch.
> 
> It's a separate change and should not be hidden away in a tree-wide
> change that goes through a different maintainer.
> 
> Please drop this change from this patch and resubmit it separately to me
> if you want and I'll review when I have the time.

Fine, I agree.

I see those options (let me know if you see other options I have not
mentioned):

1. I add this change (taking into account also intel ice) as a separate
   patch in this series and you may just ack it and Greg could merge
   together with the serdev one.
2. I prepare an independent patch for the GNSS change and only once this
   is merged I'll send a rebased v2 of this one.
3. I update this patch without this GNSS API change, that mean I will
   have to cast away the signed type from a few GNSS drivers.

1 is my preferred option, 2 is fine, but it seems a little bit of overdoing,
3 I would avoid, we are doing this cleanup to be a little bit more
strongly typed and to prevent the kind of bugs that is the original trigger
for this patch.

What would you Greg and Johan prefer?


> And when doing tree-wide changes, please try to follow the style of the
> driver you are changing (e.g. do not introduce inconsistencies by
> changing to open parenthesis alignment of continuation lines in code
> that do not use it).

ack, sorry about that, looking back at the archive is seems a recent
pain point, also Jiri fell in this trap.

Francesco

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Johan Hovold]

On Fri, Dec 15, 2023 at 06:07:33PM +0100, Francesco Dolcini wrote:

> On Fri, Dec 15, 2023 at 05:18:52PM +0100, Johan Hovold wrote:
> > On Fri, Dec 15, 2023 at 02:55:59PM +0100, Francesco Dolcini wrote:
> > > To me the change is correct, with that said probably this should have
> > > been explicitly mentioned in the commit message or a separate
> > > preparation patch.
> > 
> > It's a separate change and should not be hidden away in a tree-wide
> > change that goes through a different maintainer.
> > 
> > Please drop this change from this patch and resubmit it separately to me
> > if you want and I'll review when I have the time.
> 
> Fine, I agree.
> 
> I see those options (let me know if you see other options I have not
> mentioned):
> 
> 1. I add this change (taking into account also intel ice) as a separate
>    patch in this series and you may just ack it and Greg could merge
>    together with the serdev one.
> 2. I prepare an independent patch for the GNSS change and only once this
>    is merged I'll send a rebased v2 of this one.
> 3. I update this patch without this GNSS API change, that mean I will
>    have to cast away the signed type from a few GNSS drivers.
> 
> 1 is my preferred option, 2 is fine, but it seems a little bit of overdoing,
> 3 I would avoid, we are doing this cleanup to be a little bit more
> strongly typed and to prevent the kind of bugs that is the original trigger
> for this patch.

Changing the return type of gnss_insert_raw() is going to be a bit more
involved and should be done in a separate patch (e.g. you need to look
at gnss_usb_rx_complete() and ice_gnss_read() to avoid introducing new
warnings there).

And both option 2 and 3 will introduce conversion warnings (W=3, which
we have plenty of anyway) unless you add casts.

I suggest you go with 3, unless you insist on 2.

Johan

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Greg Kroah-Hartman]

On Fri, Dec 15, 2023 at 02:36:31PM +0100, Johan Hovold wrote:
> On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > 
> > receive_buf() is called from ttyport_receive_buf() that expects values
> > ">= 0" from serdev_controller_receive_buf(), change its return type from
> > ssize_t to size_t.
> > 
> > Suggested-by: Jiri Slaby <jirislaby@kernel.org>
> > Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
> > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > ---
> >  drivers/gnss/core.c                        |  6 +++---
> >  drivers/gnss/serial.c                      |  4 ++--
> >  drivers/gnss/sirf.c                        |  6 +++---
> 
> > diff --git a/drivers/gnss/core.c b/drivers/gnss/core.c
> > index 48f2ee0f78c4..9b8a0605ec76 100644
> > --- a/drivers/gnss/core.c
> > +++ b/drivers/gnss/core.c
> > @@ -317,10 +317,10 @@ EXPORT_SYMBOL_GPL(gnss_deregister_device);
> >   *
> >   * Must not be called for a closed device.
> >   */
> > -int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> > -				size_t count)
> > +size_t gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> > +		       size_t count)
> >  {
> > -	int ret;
> > +	size_t ret;
> >  
> >  	ret = kfifo_in(&gdev->read_fifo, buf, count);
> >  
> 
> Why are you changing this function? This is part of the GNSS interface
> and has nothing to do with the rest of this patch.
> 
> Greg, please drop this one again until this has been resolved.

Now dropped, thanks.

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Johan Hovold]

On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> From: Francesco Dolcini <francesco.dolcini@toradex.com>
> 
> receive_buf() is called from ttyport_receive_buf() that expects values
> ">= 0" from serdev_controller_receive_buf(), change its return type from
> ssize_t to size_t.
> 
> Suggested-by: Jiri Slaby <jirislaby@kernel.org>
> Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> ---
> hello,
> patch is based on current linux next.
> 
> It has an obvious problem, it touches files from multiple subsystem in a single
> patch that is complicated to review and eventually merge, just splitting this
> would however not work, it will break bisectability and the build.
> 
> I am looking for advise on the best way to move forward.
> 
> I see the following options:
>  - keep it as it is
>  - break it down with a patch with each subsystem, and squash before applying
>    from a single (tty?) subsystem
>  - go for a multi stage approach, defining a new callback, move to it and in
>    the end remove the original one, likewise it was done for i2c lately
> 
> ---
>  drivers/bluetooth/btmtkuart.c              |  4 ++--
>  drivers/bluetooth/btnxpuart.c              |  4 ++--

> diff --git a/drivers/bluetooth/btmtkuart.c b/drivers/bluetooth/btmtkuart.c
> index 3c84fcbda01a..e6bc4a73c9fc 100644
> --- a/drivers/bluetooth/btmtkuart.c
> +++ b/drivers/bluetooth/btmtkuart.c
> @@ -383,8 +383,8 @@ static void btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
>  	}
>  }
>  
> -static ssize_t btmtkuart_receive_buf(struct serdev_device *serdev,
> -				     const u8 *data, size_t count)
> +static size_t btmtkuart_receive_buf(struct serdev_device *serdev,
> +				    const u8 *data, size_t count)
>  {
>  	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
>  
> diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
> index 1d592ac413d1..056bef5b2919 100644
> --- a/drivers/bluetooth/btnxpuart.c
> +++ b/drivers/bluetooth/btnxpuart.c
> @@ -1264,8 +1264,8 @@ static const struct h4_recv_pkt nxp_recv_pkts[] = {
>  	{ NXP_RECV_FW_REQ_V3,   .recv = nxp_recv_fw_req_v3 },
>  };
>  
> -static ssize_t btnxpuart_receive_buf(struct serdev_device *serdev,
> -				     const u8 *data, size_t count)
> +static size_t btnxpuart_receive_buf(struct serdev_device *serdev,
> +				    const u8 *data, size_t count)
>  {
>  	struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);

A quick check of just the first two functions here shows that they can
return negative values.

> diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
> index e94e090cf0a1..3d7ae7fa5018 100644
> --- a/drivers/tty/serdev/serdev-ttyport.c
> +++ b/drivers/tty/serdev/serdev-ttyport.c
> @@ -27,19 +27,17 @@ static size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp,
>  {
>  	struct serdev_controller *ctrl = port->client_data;
>  	struct serport *serport = serdev_controller_get_drvdata(ctrl);
> -	int ret;
> +	size_t ret;
>  
>  	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
>  		return 0;
>  
>  	ret = serdev_controller_receive_buf(ctrl, cp, count);
>  
> -	dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
> -				"receive_buf returns %d (count = %zu)\n",
> +	dev_WARN_ONCE(&ctrl->dev, ret > count,
> +				"receive_buf returns %zu (count = %zu)\n",
>  				ret, count);
> -	if (ret < 0)
> -		return 0;
> -	else if (ret > count)
> +	if (ret > count)
>  		return count;
>  
>  	return ret;

So please do not apply this patch until the various implementations have
been fixed.

Johan

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Francesco Dolcini]

On Fri, Dec 15, 2023 at 02:51:09PM +0100, Johan Hovold wrote:
> On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > 
> > receive_buf() is called from ttyport_receive_buf() that expects values
> > ">= 0" from serdev_controller_receive_buf(), change its return type from
> > ssize_t to size_t.
> > 
> > Suggested-by: Jiri Slaby <jirislaby@kernel.org>
> > Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
> > Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > ---
> > hello,
> > patch is based on current linux next.
> > 
> > It has an obvious problem, it touches files from multiple subsystem in a single
> > patch that is complicated to review and eventually merge, just splitting this
> > would however not work, it will break bisectability and the build.
> > 
> > I am looking for advise on the best way to move forward.
> > 
> > I see the following options:
> >  - keep it as it is
> >  - break it down with a patch with each subsystem, and squash before applying
> >    from a single (tty?) subsystem
> >  - go for a multi stage approach, defining a new callback, move to it and in
> >    the end remove the original one, likewise it was done for i2c lately
> > 
> > ---
> >  drivers/bluetooth/btmtkuart.c              |  4 ++--
> >  drivers/bluetooth/btnxpuart.c              |  4 ++--
> 
> > diff --git a/drivers/bluetooth/btmtkuart.c b/drivers/bluetooth/btmtkuart.c
> > index 3c84fcbda01a..e6bc4a73c9fc 100644
> > --- a/drivers/bluetooth/btmtkuart.c
> > +++ b/drivers/bluetooth/btmtkuart.c
> > @@ -383,8 +383,8 @@ static void btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
> >  	}
> >  }
> >  
> > -static ssize_t btmtkuart_receive_buf(struct serdev_device *serdev,
> > -				     const u8 *data, size_t count)
> > +static size_t btmtkuart_receive_buf(struct serdev_device *serdev,
> > +				    const u8 *data, size_t count)
> >  {
> >  	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
> >  
> > diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
> > index 1d592ac413d1..056bef5b2919 100644
> > --- a/drivers/bluetooth/btnxpuart.c
> > +++ b/drivers/bluetooth/btnxpuart.c
> > @@ -1264,8 +1264,8 @@ static const struct h4_recv_pkt nxp_recv_pkts[] = {
> >  	{ NXP_RECV_FW_REQ_V3,   .recv = nxp_recv_fw_req_v3 },
> >  };
> >  
> > -static ssize_t btnxpuart_receive_buf(struct serdev_device *serdev,
> > -				     const u8 *data, size_t count)
> > +static size_t btnxpuart_receive_buf(struct serdev_device *serdev,
> > +				    const u8 *data, size_t count)
> >  {
> >  	struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
> 
> A quick check of just the first two functions here shows that they can
> return negative values.

This is already fixed. Patches are in next.

There were 3 buggy user of this API.
 - 1 patch was merged a few days ago in mainline
 - 2 patches are in next, the maintainer decided to wait for the next merge window

commit 687d2de93b11 ("Bluetooth: btmtkuart: fix recv_buf() return value")
commit 7954bbcdd7ea ("Bluetooth: btnxpuart: fix recv_buf() return value")
commit c8820c92caf0 ("platform/surface: aggregator: fix recv_buf() return value")


> 
> > diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
> > index e94e090cf0a1..3d7ae7fa5018 100644
> > --- a/drivers/tty/serdev/serdev-ttyport.c
> > +++ b/drivers/tty/serdev/serdev-ttyport.c
> > @@ -27,19 +27,17 @@ static size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp,
> >  {
> >  	struct serdev_controller *ctrl = port->client_data;
> >  	struct serport *serport = serdev_controller_get_drvdata(ctrl);
> > -	int ret;
> > +	size_t ret;
> >  
> >  	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
> >  		return 0;
> >  
> >  	ret = serdev_controller_receive_buf(ctrl, cp, count);
> >  
> > -	dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
> > -				"receive_buf returns %d (count = %zu)\n",
> > +	dev_WARN_ONCE(&ctrl->dev, ret > count,
> > +				"receive_buf returns %zu (count = %zu)\n",
> >  				ret, count);
> > -	if (ret < 0)
> > -		return 0;
> > -	else if (ret > count)
> > +	if (ret > count)
> >  		return count;
> >  
> >  	return ret;
> 
> So please do not apply this patch until the various implementations have
> been fixed.
> 
> Johan

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Johan Hovold]

On Fri, Dec 15, 2023 at 02:59:35PM +0100, Francesco Dolcini wrote:
> On Fri, Dec 15, 2023 at 02:51:09PM +0100, Johan Hovold wrote:
> > On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> > > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > > 
> > > receive_buf() is called from ttyport_receive_buf() that expects values
> > > ">= 0" from serdev_controller_receive_buf(), change its return type from
> > > ssize_t to size_t.

> > >  drivers/bluetooth/btmtkuart.c              |  4 ++--
> > >  drivers/bluetooth/btnxpuart.c              |  4 ++--

> > > -static ssize_t btnxpuart_receive_buf(struct serdev_device *serdev,
> > > -				     const u8 *data, size_t count)
> > > +static size_t btnxpuart_receive_buf(struct serdev_device *serdev,
> > > +				    const u8 *data, size_t count)
> > >  {
> > >  	struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
> > 
> > A quick check of just the first two functions here shows that they can
> > return negative values.
> 
> This is already fixed. Patches are in next.
> 
> There were 3 buggy user of this API.
>  - 1 patch was merged a few days ago in mainline
>  - 2 patches are in next, the maintainer decided to wait for the next merge window
> 
> commit 687d2de93b11 ("Bluetooth: btmtkuart: fix recv_buf() return value")
> commit 7954bbcdd7ea ("Bluetooth: btnxpuart: fix recv_buf() return value")
> commit c8820c92caf0 ("platform/surface: aggregator: fix recv_buf() return value")

Then why was that not mentioned in the patch (e.g. below the --- line)?

You are certainly not making it easy for reviewers, but good to see that
you thought about this, and I see now when reviewing the mail archives
that those bugs were the reason for this patch in the first place.

Johan

Re: [PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Jonathan Cameron]

On Thu, 14 Dec 2023 18:01:46 +0100
Francesco Dolcini <francesco@dolcini.it> wrote:

> From: Francesco Dolcini <francesco.dolcini@toradex.com>
> 
> receive_buf() is called from ttyport_receive_buf() that expects values
> ">= 0" from serdev_controller_receive_buf(), change its return type from  
> ssize_t to size_t.
> 
> Suggested-by: Jiri Slaby <jirislaby@kernel.org>
> Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>

IIO ones look fine to me so for next version

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for-iio
> ---
> hello,
> patch is based on current linux next.
> 
> It has an obvious problem, it touches files from multiple subsystem in a single
> patch that is complicated to review and eventually merge, just splitting this
> would however not work, it will break bisectability and the build.
> 
> I am looking for advise on the best way to move forward.
> 
> I see the following options:
>  - keep it as it is
>  - break it down with a patch with each subsystem, and squash before applying
>    from a single (tty?) subsystem
>  - go for a multi stage approach, defining a new callback, move to it and in
>    the end remove the original one, likewise it was done for i2c lately
> 
> ---
>  drivers/bluetooth/btmtkuart.c              |  4 ++--
>  drivers/bluetooth/btnxpuart.c              |  4 ++--
>  drivers/bluetooth/hci_serdev.c             |  4 ++--
>  drivers/gnss/core.c                        |  6 +++---
>  drivers/gnss/serial.c                      |  4 ++--
>  drivers/gnss/sirf.c                        |  6 +++---
>  drivers/greybus/gb-beagleplay.c            |  6 +++---
>  drivers/iio/chemical/pms7003.c             |  4 ++--
>  drivers/iio/chemical/scd30_serial.c        |  4 ++--
>  drivers/iio/chemical/sps30_serial.c        |  4 ++--
>  drivers/iio/imu/bno055/bno055_ser_core.c   |  4 ++--
>  drivers/mfd/rave-sp.c                      |  4 ++--
>  drivers/net/ethernet/qualcomm/qca_uart.c   |  2 +-
>  drivers/nfc/pn533/uart.c                   |  4 ++--
>  drivers/nfc/s3fwrn5/uart.c                 |  4 ++--
>  drivers/platform/chrome/cros_ec_uart.c     |  4 ++--
>  drivers/platform/surface/aggregator/core.c |  4 ++--
>  drivers/tty/serdev/serdev-ttyport.c        | 10 ++++------
>  include/linux/gnss.h                       |  4 ++--
>  include/linux/serdev.h                     |  8 ++++----
>  sound/drivers/serial-generic.c             |  4 ++--
>  21 files changed, 48 insertions(+), 50 deletions(-)
> 
> diff --git a/drivers/bluetooth/btmtkuart.c b/drivers/bluetooth/btmtkuart.c
> index 3c84fcbda01a..e6bc4a73c9fc 100644
> --- a/drivers/bluetooth/btmtkuart.c
> +++ b/drivers/bluetooth/btmtkuart.c
> @@ -383,8 +383,8 @@ static void btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
>  	}
>  }
>  
> -static ssize_t btmtkuart_receive_buf(struct serdev_device *serdev,
> -				     const u8 *data, size_t count)
> +static size_t btmtkuart_receive_buf(struct serdev_device *serdev,
> +				    const u8 *data, size_t count)
>  {
>  	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
>  
> diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
> index 1d592ac413d1..056bef5b2919 100644
> --- a/drivers/bluetooth/btnxpuart.c
> +++ b/drivers/bluetooth/btnxpuart.c
> @@ -1264,8 +1264,8 @@ static const struct h4_recv_pkt nxp_recv_pkts[] = {
>  	{ NXP_RECV_FW_REQ_V3,   .recv = nxp_recv_fw_req_v3 },
>  };
>  
> -static ssize_t btnxpuart_receive_buf(struct serdev_device *serdev,
> -				     const u8 *data, size_t count)
> +static size_t btnxpuart_receive_buf(struct serdev_device *serdev,
> +				    const u8 *data, size_t count)
>  {
>  	struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
>  
> diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
> index 39c8b567da3c..a3c3beb2806d 100644
> --- a/drivers/bluetooth/hci_serdev.c
> +++ b/drivers/bluetooth/hci_serdev.c
> @@ -271,8 +271,8 @@ static void hci_uart_write_wakeup(struct serdev_device *serdev)
>   *
>   * Return: number of processed bytes
>   */
> -static ssize_t hci_uart_receive_buf(struct serdev_device *serdev,
> -				    const u8 *data, size_t count)
> +static size_t hci_uart_receive_buf(struct serdev_device *serdev,
> +				   const u8 *data, size_t count)
>  {
>  	struct hci_uart *hu = serdev_device_get_drvdata(serdev);
>  
> diff --git a/drivers/gnss/core.c b/drivers/gnss/core.c
> index 48f2ee0f78c4..9b8a0605ec76 100644
> --- a/drivers/gnss/core.c
> +++ b/drivers/gnss/core.c
> @@ -317,10 +317,10 @@ EXPORT_SYMBOL_GPL(gnss_deregister_device);
>   *
>   * Must not be called for a closed device.
>   */
> -int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> -				size_t count)
> +size_t gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> +		       size_t count)
>  {
> -	int ret;
> +	size_t ret;
>  
>  	ret = kfifo_in(&gdev->read_fifo, buf, count);
>  
> diff --git a/drivers/gnss/serial.c b/drivers/gnss/serial.c
> index baa956494e79..bf55aa2c1cf0 100644
> --- a/drivers/gnss/serial.c
> +++ b/drivers/gnss/serial.c
> @@ -80,8 +80,8 @@ static const struct gnss_operations gnss_serial_gnss_ops = {
>  	.write_raw	= gnss_serial_write_raw,
>  };
>  
> -static ssize_t gnss_serial_receive_buf(struct serdev_device *serdev,
> -				       const u8 *buf, size_t count)
> +static size_t gnss_serial_receive_buf(struct serdev_device *serdev,
> +				      const u8 *buf, size_t count)
>  {
>  	struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
>  	struct gnss_device *gdev = gserial->gdev;
> diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c
> index 6801a8fb2040..2aae3c02156d 100644
> --- a/drivers/gnss/sirf.c
> +++ b/drivers/gnss/sirf.c
> @@ -160,12 +160,12 @@ static const struct gnss_operations sirf_gnss_ops = {
>  	.write_raw	= sirf_write_raw,
>  };
>  
> -static ssize_t sirf_receive_buf(struct serdev_device *serdev,
> -				const u8 *buf, size_t count)
> +static size_t sirf_receive_buf(struct serdev_device *serdev,
> +			       const u8 *buf, size_t count)
>  {
>  	struct sirf_data *data = serdev_device_get_drvdata(serdev);
>  	struct gnss_device *gdev = data->gdev;
> -	int ret = 0;
> +	size_t ret = 0;
>  
>  	if (!data->wakeup && !data->active) {
>  		data->active = true;
> diff --git a/drivers/greybus/gb-beagleplay.c b/drivers/greybus/gb-beagleplay.c
> index 2da37ff92cf1..26c95efe2fff 100644
> --- a/drivers/greybus/gb-beagleplay.c
> +++ b/drivers/greybus/gb-beagleplay.c
> @@ -257,7 +257,7 @@ static void hdlc_rx_frame(struct gb_beagleplay *bg)
>  	}
>  }
>  
> -static ssize_t hdlc_rx(struct gb_beagleplay *bg, const u8 *data, size_t count)
> +static size_t hdlc_rx(struct gb_beagleplay *bg, const u8 *data, size_t count)
>  {
>  	size_t i;
>  	u8 c;
> @@ -317,8 +317,8 @@ static void hdlc_deinit(struct gb_beagleplay *bg)
>  	flush_work(&bg->tx_work);
>  }
>  
> -static ssize_t gb_tty_receive(struct serdev_device *sd, const u8 *data,
> -			      size_t count)
> +static size_t gb_tty_receive(struct serdev_device *sd, const u8 *data,
> +			     size_t count)
>  {
>  	struct gb_beagleplay *bg = serdev_device_get_drvdata(sd);
>  
> diff --git a/drivers/iio/chemical/pms7003.c b/drivers/iio/chemical/pms7003.c
> index b5cf15a515d2..43025866d5b7 100644
> --- a/drivers/iio/chemical/pms7003.c
> +++ b/drivers/iio/chemical/pms7003.c
> @@ -211,8 +211,8 @@ static bool pms7003_frame_is_okay(struct pms7003_frame *frame)
>  	return checksum == pms7003_calc_checksum(frame);
>  }
>  
> -static ssize_t pms7003_receive_buf(struct serdev_device *serdev, const u8 *buf,
> -				   size_t size)
> +static size_t pms7003_receive_buf(struct serdev_device *serdev, const u8 *buf,
> +				  size_t size)
>  {
>  	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
>  	struct pms7003_state *state = iio_priv(indio_dev);
> diff --git a/drivers/iio/chemical/scd30_serial.c b/drivers/iio/chemical/scd30_serial.c
> index a47654591e55..2adb76dbb020 100644
> --- a/drivers/iio/chemical/scd30_serial.c
> +++ b/drivers/iio/chemical/scd30_serial.c
> @@ -174,8 +174,8 @@ static int scd30_serdev_command(struct scd30_state *state, enum scd30_cmd cmd, u
>  	return 0;
>  }
>  
> -static ssize_t scd30_serdev_receive_buf(struct serdev_device *serdev,
> -					const u8 *buf, size_t size)
> +static size_t scd30_serdev_receive_buf(struct serdev_device *serdev,
> +				       const u8 *buf, size_t size)
>  {
>  	struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
>  	struct scd30_serdev_priv *priv;
> diff --git a/drivers/iio/chemical/sps30_serial.c b/drivers/iio/chemical/sps30_serial.c
> index 3afa89f8acc3..a6dfbe28c914 100644
> --- a/drivers/iio/chemical/sps30_serial.c
> +++ b/drivers/iio/chemical/sps30_serial.c
> @@ -210,8 +210,8 @@ static int sps30_serial_command(struct sps30_state *state, unsigned char cmd,
>  	return rsp_size;
>  }
>  
> -static ssize_t sps30_serial_receive_buf(struct serdev_device *serdev,
> -					const u8 *buf, size_t size)
> +static size_t sps30_serial_receive_buf(struct serdev_device *serdev,
> +				       const u8 *buf, size_t size)
>  {
>  	struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev);
>  	struct sps30_serial_priv *priv;
> diff --git a/drivers/iio/imu/bno055/bno055_ser_core.c b/drivers/iio/imu/bno055/bno055_ser_core.c
> index 5677bdf4f846..694ff14a3aa2 100644
> --- a/drivers/iio/imu/bno055/bno055_ser_core.c
> +++ b/drivers/iio/imu/bno055/bno055_ser_core.c
> @@ -378,8 +378,8 @@ static void bno055_ser_handle_rx(struct bno055_ser_priv *priv, int status)
>   * Also, we assume to RX one pkt per time (i.e. the HW doesn't send anything
>   * unless we require to AND we don't queue more than one request per time).
>   */
> -static ssize_t bno055_ser_receive_buf(struct serdev_device *serdev,
> -				      const u8 *buf, size_t size)
> +static size_t bno055_ser_receive_buf(struct serdev_device *serdev,
> +				     const u8 *buf, size_t size)
>  {
>  	int status;
>  	struct bno055_ser_priv *priv = serdev_device_get_drvdata(serdev);
> diff --git a/drivers/mfd/rave-sp.c b/drivers/mfd/rave-sp.c
> index b1229bb143ee..f517e59e1c01 100644
> --- a/drivers/mfd/rave-sp.c
> +++ b/drivers/mfd/rave-sp.c
> @@ -471,8 +471,8 @@ static void rave_sp_receive_frame(struct rave_sp *sp,
>  		rave_sp_receive_reply(sp, data, length);
>  }
>  
> -static ssize_t rave_sp_receive_buf(struct serdev_device *serdev,
> -				   const u8 *buf, size_t size)
> +static size_t rave_sp_receive_buf(struct serdev_device *serdev,
> +				  const u8 *buf, size_t size)
>  {
>  	struct device *dev = &serdev->dev;
>  	struct rave_sp *sp = dev_get_drvdata(dev);
> diff --git a/drivers/net/ethernet/qualcomm/qca_uart.c b/drivers/net/ethernet/qualcomm/qca_uart.c
> index 223321897b96..20f50bde82ac 100644
> --- a/drivers/net/ethernet/qualcomm/qca_uart.c
> +++ b/drivers/net/ethernet/qualcomm/qca_uart.c
> @@ -58,7 +58,7 @@ struct qcauart {
>  	unsigned char *tx_buffer;
>  };
>  
> -static ssize_t
> +static size_t
>  qca_tty_receive(struct serdev_device *serdev, const u8 *data, size_t count)
>  {
>  	struct qcauart *qca = serdev_device_get_drvdata(serdev);
> diff --git a/drivers/nfc/pn533/uart.c b/drivers/nfc/pn533/uart.c
> index 2eb5978bd79e..cfbbe0713317 100644
> --- a/drivers/nfc/pn533/uart.c
> +++ b/drivers/nfc/pn533/uart.c
> @@ -203,8 +203,8 @@ static int pn532_uart_rx_is_frame(struct sk_buff *skb)
>  	return 0;
>  }
>  
> -static ssize_t pn532_receive_buf(struct serdev_device *serdev,
> -				 const u8 *data, size_t count)
> +static size_t pn532_receive_buf(struct serdev_device *serdev,
> +				const u8 *data, size_t count)
>  {
>  	struct pn532_uart_phy *dev = serdev_device_get_drvdata(serdev);
>  	size_t i;
> diff --git a/drivers/nfc/s3fwrn5/uart.c b/drivers/nfc/s3fwrn5/uart.c
> index 456d3947116c..9c09c10c2a46 100644
> --- a/drivers/nfc/s3fwrn5/uart.c
> +++ b/drivers/nfc/s3fwrn5/uart.c
> @@ -51,8 +51,8 @@ static const struct s3fwrn5_phy_ops uart_phy_ops = {
>  	.write = s3fwrn82_uart_write,
>  };
>  
> -static ssize_t s3fwrn82_uart_read(struct serdev_device *serdev,
> -				  const u8 *data, size_t count)
> +static size_t s3fwrn82_uart_read(struct serdev_device *serdev,
> +				 const u8 *data, size_t count)
>  {
>  	struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);
>  	size_t i;
> diff --git a/drivers/platform/chrome/cros_ec_uart.c b/drivers/platform/chrome/cros_ec_uart.c
> index 68d80559fddc..8ea867c2a01a 100644
> --- a/drivers/platform/chrome/cros_ec_uart.c
> +++ b/drivers/platform/chrome/cros_ec_uart.c
> @@ -81,8 +81,8 @@ struct cros_ec_uart {
>  	struct response_info response;
>  };
>  
> -static ssize_t cros_ec_uart_rx_bytes(struct serdev_device *serdev,
> -				     const u8 *data, size_t count)
> +static size_t cros_ec_uart_rx_bytes(struct serdev_device *serdev,
> +				    const u8 *data, size_t count)
>  {
>  	struct ec_host_response *host_response;
>  	struct cros_ec_device *ec_dev = serdev_device_get_drvdata(serdev);
> diff --git a/drivers/platform/surface/aggregator/core.c b/drivers/platform/surface/aggregator/core.c
> index 9591a28bc38a..ba550eaa06fc 100644
> --- a/drivers/platform/surface/aggregator/core.c
> +++ b/drivers/platform/surface/aggregator/core.c
> @@ -227,8 +227,8 @@ EXPORT_SYMBOL_GPL(ssam_client_bind);
>  
>  /* -- Glue layer (serdev_device -> ssam_controller). ------------------------ */
>  
> -static ssize_t ssam_receive_buf(struct serdev_device *dev, const u8 *buf,
> -				size_t n)
> +static size_t ssam_receive_buf(struct serdev_device *dev, const u8 *buf,
> +			       size_t n)
>  {
>  	struct ssam_controller *ctrl;
>  	int ret;
> diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
> index e94e090cf0a1..3d7ae7fa5018 100644
> --- a/drivers/tty/serdev/serdev-ttyport.c
> +++ b/drivers/tty/serdev/serdev-ttyport.c
> @@ -27,19 +27,17 @@ static size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp,
>  {
>  	struct serdev_controller *ctrl = port->client_data;
>  	struct serport *serport = serdev_controller_get_drvdata(ctrl);
> -	int ret;
> +	size_t ret;
>  
>  	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
>  		return 0;
>  
>  	ret = serdev_controller_receive_buf(ctrl, cp, count);
>  
> -	dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
> -				"receive_buf returns %d (count = %zu)\n",
> +	dev_WARN_ONCE(&ctrl->dev, ret > count,
> +				"receive_buf returns %zu (count = %zu)\n",
>  				ret, count);
> -	if (ret < 0)
> -		return 0;
> -	else if (ret > count)
> +	if (ret > count)
>  		return count;
>  
>  	return ret;
> diff --git a/include/linux/gnss.h b/include/linux/gnss.h
> index 36968a0f33e8..9857c4029e65 100644
> --- a/include/linux/gnss.h
> +++ b/include/linux/gnss.h
> @@ -60,8 +60,8 @@ void gnss_put_device(struct gnss_device *gdev);
>  int gnss_register_device(struct gnss_device *gdev);
>  void gnss_deregister_device(struct gnss_device *gdev);
>  
> -int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> -			size_t count);
> +size_t gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf,
> +		       size_t count);
>  
>  static inline void gnss_set_drvdata(struct gnss_device *gdev, void *data)
>  {
> diff --git a/include/linux/serdev.h b/include/linux/serdev.h
> index 3fab88ba265e..ff78efc1f60d 100644
> --- a/include/linux/serdev.h
> +++ b/include/linux/serdev.h
> @@ -27,7 +27,7 @@ struct serdev_device;
>   *			not sleep.
>   */
>  struct serdev_device_ops {
> -	ssize_t (*receive_buf)(struct serdev_device *, const u8 *, size_t);
> +	size_t (*receive_buf)(struct serdev_device *, const u8 *, size_t);
>  	void (*write_wakeup)(struct serdev_device *);
>  };
>  
> @@ -185,9 +185,9 @@ static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl
>  	serdev->ops->write_wakeup(serdev);
>  }
>  
> -static inline ssize_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
> -						    const u8 *data,
> -						    size_t count)
> +static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
> +						   const u8 *data,
> +						   size_t count)
>  {
>  	struct serdev_device *serdev = ctrl->serdev;
>  
> diff --git a/sound/drivers/serial-generic.c b/sound/drivers/serial-generic.c
> index d6e5aafd697c..36409a56c675 100644
> --- a/sound/drivers/serial-generic.c
> +++ b/sound/drivers/serial-generic.c
> @@ -100,8 +100,8 @@ static void snd_serial_generic_write_wakeup(struct serdev_device *serdev)
>  	snd_serial_generic_tx_wakeup(drvdata);
>  }
>  
> -static ssize_t snd_serial_generic_receive_buf(struct serdev_device *serdev,
> -					      const u8 *buf, size_t count)
> +static size_t snd_serial_generic_receive_buf(struct serdev_device *serdev,
> +					     const u8 *buf, size_t count)
>  {
>  	int ret;
>  	struct snd_serial_generic *drvdata = serdev_device_get_drvdata(serdev);
> 
> base-commit: 11651f8cb2e88372d4ed523d909514dc9a613ea3