[Eoan,Disco,1/1] Bluetooth: hidp: Fix assumptions on the return value of hidp_send_message

From: Dan Elkouby <streetwalkermc@gmail.com>

BugLink: https://bugs.launchpad.net/bugs/1850443

hidp_send_message was changed to return non-zero values on success,
which some other bits did not expect. This caused spurious errors to be
propagated through the stack, breaking some drivers, such as hid-sony
for the Dualshock 4 in Bluetooth mode.

As pointed out by Dan Carpenter, hid-microsoft directly relied on that
assumption as well.

Fixes: 48d9cc9d85dd ("Bluetooth: hidp: Let hidp_send_message return number of queued bytes")

Signed-off-by: Dan Elkouby <streetwalkermc@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
(cherry picked from commit 8bb3537095f107ed55ad51f6241165b397aaafac)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/hid/hid-microsoft.c | 2 +-
 net/bluetooth/hidp/core.c   | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

On 29.10.19 17:25, Kamal Mostafa wrote:
> From: Dan Elkouby <streetwalkermc@gmail.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1850443
> 
> hidp_send_message was changed to return non-zero values on success,
> which some other bits did not expect. This caused spurious errors to be
> propagated through the stack, breaking some drivers, such as hid-sony
> for the Dualshock 4 in Bluetooth mode.
> 
> As pointed out by Dan Carpenter, hid-microsoft directly relied on that
> assumption as well.
> 
> Fixes: 48d9cc9d85dd ("Bluetooth: hidp: Let hidp_send_message return number of queued bytes")
> 
> Signed-off-by: Dan Elkouby <streetwalkermc@gmail.com>
> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
> Reviewed-by: Jiri Kosina <jkosina@suse.cz>
> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
> (cherry picked from commit 8bb3537095f107ed55ad51f6241165b397aaafac)
> Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
> ---

Bug report should have proper SRU justification in the description.

-Stefan
>  drivers/hid/hid-microsoft.c | 2 +-
>  net/bluetooth/hidp/core.c   | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hid/hid-microsoft.c b/drivers/hid/hid-microsoft.c
> index 8b3a922bdad3..2cf83856f2e4 100644
> --- a/drivers/hid/hid-microsoft.c
> +++ b/drivers/hid/hid-microsoft.c
> @@ -303,7 +303,7 @@ static void ms_ff_worker(struct work_struct *work)
>  	r->magnitude[MAGNITUDE_WEAK] = ms->weak;     /* right actuator */
>  
>  	ret = hid_hw_output_report(hdev, (__u8 *)r, sizeof(*r));
> -	if (ret)
> +	if (ret < 0)
>  		hid_warn(hdev, "failed to send FF report\n");
>  }
>  
> diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c
> index 8d889969ae7e..bef84b95e2c4 100644
> --- a/net/bluetooth/hidp/core.c
> +++ b/net/bluetooth/hidp/core.c
> @@ -267,7 +267,7 @@ static int hidp_get_raw_report(struct hid_device *hid,
>  	set_bit(HIDP_WAITING_FOR_RETURN, &session->flags);
>  	data[0] = report_number;
>  	ret = hidp_send_ctrl_message(session, report_type, data, 1);
> -	if (ret)
> +	if (ret < 0)
>  		goto err;
>  
>  	/* Wait for the return of the report. The returned report
> @@ -343,7 +343,7 @@ static int hidp_set_raw_report(struct hid_device *hid, unsigned char reportnum,
>  	data[0] = reportnum;
>  	set_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
>  	ret = hidp_send_ctrl_message(session, report_type, data, count);
> -	if (ret)
> +	if (ret < 0)
>  		goto err;
>  
>  	/* Wait for the ACK from the device. */
>

On 10/29/19 9:25 AM, Kamal Mostafa wrote:
> From: Dan Elkouby <streetwalkermc@gmail.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1850443
> 
> hidp_send_message was changed to return non-zero values on success,
> which some other bits did not expect. This caused spurious errors to be
> propagated through the stack, breaking some drivers, such as hid-sony
> for the Dualshock 4 in Bluetooth mode.
> 
> As pointed out by Dan Carpenter, hid-microsoft directly relied on that
> assumption as well.
> 
> Fixes: 48d9cc9d85dd ("Bluetooth: hidp: Let hidp_send_message return number of queued bytes")
> 
> Signed-off-by: Dan Elkouby <streetwalkermc@gmail.com>
> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
> Reviewed-by: Jiri Kosina <jkosina@suse.cz>
> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
> (cherry picked from commit 8bb3537095f107ed55ad51f6241165b397aaafac)
> Signed-off-by: Kamal Mostafa <kamal@canonical.com>

Acked-by: Connor Kuehl <connor.kuehl@canonical.com>

> ---
>   drivers/hid/hid-microsoft.c | 2 +-
>   net/bluetooth/hidp/core.c   | 4 ++--
>   2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hid/hid-microsoft.c b/drivers/hid/hid-microsoft.c
> index 8b3a922bdad3..2cf83856f2e4 100644
> --- a/drivers/hid/hid-microsoft.c
> +++ b/drivers/hid/hid-microsoft.c
> @@ -303,7 +303,7 @@ static void ms_ff_worker(struct work_struct *work)
>   	r->magnitude[MAGNITUDE_WEAK] = ms->weak;     /* right actuator */
>   
>   	ret = hid_hw_output_report(hdev, (__u8 *)r, sizeof(*r));
> -	if (ret)
> +	if (ret < 0)
>   		hid_warn(hdev, "failed to send FF report\n");
>   }
>   
> diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c
> index 8d889969ae7e..bef84b95e2c4 100644
> --- a/net/bluetooth/hidp/core.c
> +++ b/net/bluetooth/hidp/core.c
> @@ -267,7 +267,7 @@ static int hidp_get_raw_report(struct hid_device *hid,
>   	set_bit(HIDP_WAITING_FOR_RETURN, &session->flags);
>   	data[0] = report_number;
>   	ret = hidp_send_ctrl_message(session, report_type, data, 1);
> -	if (ret)
> +	if (ret < 0)
>   		goto err;
>   
>   	/* Wait for the return of the report. The returned report
> @@ -343,7 +343,7 @@ static int hidp_set_raw_report(struct hid_device *hid, unsigned char reportnum,
>   	data[0] = reportnum;
>   	set_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
>   	ret = hidp_send_ctrl_message(session, report_type, data, count);
> -	if (ret)
> +	if (ret < 0)
>   		goto err;
>   
>   	/* Wait for the ACK from the device. */
>