| Message ID | 20240318123712.9729-2-mahesh.talewad@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | LE Create Connection command timeout changed to 20 secs | expand |
| Context | Check | Description |
|---|---|---|
| tedd_an/pre-ci_am | success | Success |
| tedd_an/CheckPatch | success | CheckPatch PASS |
| tedd_an/GitLint | fail | WARNING: I3 - ignore-body-lines: gitlint will be switching from using Python regex 'match' (match beginning) to 'search' (match anywhere) semantics. Please review your ignore-body-lines.regex option accordingly. To remove this warning, set general.regex-style-search=True. More details: https://jorisroovers.github.io/gitlint/configuration/#regex-style-search 1: T1 Title exceeds max length (84>80): "[BlueZ,v1,1/1] LE Create Connection command timeout increased to 20 secs from 4 secs" |
| tedd_an/SubjectPrefix | fail | "Bluetooth: " prefix is not specified in the subject |
| tedd_an/BuildKernel | success | BuildKernel PASS |
| tedd_an/CheckAllWarning | success | CheckAllWarning PASS |
| tedd_an/CheckSparse | warning | CheckSparse WARNING net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h): |
| tedd_an/CheckSmatch | warning | CheckSparse WARNING net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h): |
| tedd_an/BuildKernel32 | success | BuildKernel32 PASS |
| tedd_an/TestRunnerSetup | success | TestRunnerSetup PASS |
| tedd_an/TestRunner_l2cap-tester | success | TestRunner PASS |
| tedd_an/TestRunner_iso-tester | fail | TestRunner_iso-tester: Total: 117, Passed: 116 (99.1%), Failed: 1, Not Run: 0 |
| tedd_an/TestRunner_bnep-tester | success | TestRunner PASS |
| tedd_an/TestRunner_mgmt-tester | fail | TestRunner_mgmt-tester: Total: 492, Passed: 489 (99.4%), Failed: 1, Not Run: 2 |
| tedd_an/TestRunner_rfcomm-tester | success | TestRunner PASS |
| tedd_an/TestRunner_sco-tester | success | TestRunner PASS |
| tedd_an/TestRunner_ioctl-tester | success | TestRunner PASS |
| tedd_an/TestRunner_mesh-tester | success | TestRunner PASS |
| tedd_an/TestRunner_smp-tester | success | TestRunner PASS |
| tedd_an/TestRunner_userchan-tester | success | TestRunner PASS |
| tedd_an/IncrementalBuild | success | Incremental Build PASS |
This is automated email and please do not reply to this email! Dear submitter, Thank you for submitting the patches to the linux bluetooth mailing list. This is a CI test results with your patch series: PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=836066 ---Test result--- Test Summary: CheckPatch PASS 0.49 seconds GitLint FAIL 0.47 seconds SubjectPrefix FAIL 0.32 seconds BuildKernel PASS 27.83 seconds CheckAllWarning PASS 32.20 seconds CheckSparse WARNING 36.11 seconds CheckSmatch WARNING 98.74 seconds BuildKernel32 PASS 27.90 seconds TestRunnerSetup PASS 517.55 seconds TestRunner_l2cap-tester PASS 22.12 seconds TestRunner_iso-tester FAIL 32.70 seconds TestRunner_bnep-tester PASS 4.71 seconds TestRunner_mgmt-tester FAIL 111.33 seconds TestRunner_rfcomm-tester PASS 7.35 seconds TestRunner_sco-tester PASS 12.96 seconds TestRunner_ioctl-tester PASS 7.75 seconds TestRunner_mesh-tester PASS 5.79 seconds TestRunner_smp-tester PASS 6.99 seconds TestRunner_userchan-tester PASS 4.93 seconds IncrementalBuild PASS 26.30 seconds Details ############################## Test: GitLint - FAIL Desc: Run gitlint Output: [BlueZ,v1,1/1] LE Create Connection command timeout increased to 20 secs from 4 secs WARNING: I3 - ignore-body-lines: gitlint will be switching from using Python regex 'match' (match beginning) to 'search' (match anywhere) semantics. Please review your ignore-body-lines.regex option accordingly. To remove this warning, set general.regex-style-search=True. More details: https://jorisroovers.github.io/gitlint/configuration/#regex-style-search 1: T1 Title exceeds max length (84>80): "[BlueZ,v1,1/1] LE Create Connection command timeout increased to 20 secs from 4 secs" ############################## Test: SubjectPrefix - FAIL Desc: Check subject contains "Bluetooth" prefix Output: "Bluetooth: " prefix is not specified in the subject ############################## Test: CheckSparse - WARNING Desc: Run sparse tool with linux kernel Output: net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h): ############################## Test: CheckSmatch - WARNING Desc: Run smatch tool with source Output: net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h): ############################## Test: TestRunner_iso-tester - FAIL Desc: Run iso-tester with test-runner Output: Total: 117, Passed: 116 (99.1%), Failed: 1, Not Run: 0 Failed Test Cases ISO Connect2 Suspend - Success Failed 4.211 seconds ############################## Test: TestRunner_mgmt-tester - FAIL Desc: Run mgmt-tester with test-runner Output: Total: 492, Passed: 489 (99.4%), Failed: 1, Not Run: 2 Failed Test Cases LL Privacy - Start Discovery 2 (Disable RL) Failed 0.173 seconds --- Regards, Linux Bluetooth
Hi Mahesh, On Mon, Mar 18, 2024 at 12:37 PM Mahesh Talewad <mahesh.talewad@nxp.com> wrote: > > - As per specs LE Connection timeout is 20 secs but in implementation, > it was 4 secs. Hence increased this timeout to 20 Secs. > > Signed-off-by: Mahesh Talewad <mahesh.talewad@nxp.com> > --- > net/bluetooth/hci_event.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c > index 4ae224824012..06fe5f6b9546 100644 > --- a/net/bluetooth/hci_event.c > +++ b/net/bluetooth/hci_event.c > @@ -6067,7 +6067,7 @@ static struct hci_conn *check_pending_le_conn(struct hci_dev *hdev, > } > > conn = hci_connect_le(hdev, addr, addr_type, addr_resolved, > - BT_SECURITY_LOW, hdev->def_le_autoconnect_timeout, > + BT_SECURITY_LOW, HCI_LE_CONN_TIMEOUT, > HCI_ROLE_MASTER); > if (!IS_ERR(conn)) { > /* If HCI_AUTO_CONN_EXPLICIT is set, conn is already owned > -- > 2.34.1 Afaik this is on purpose since it is the autoconnect procedure, rather than user initiate connection, so are you running into a problem if the timeout is different?
Hi Luiz, Yes, its auto connect scenario. While running connect disconnect in a loop on one of the chip, we are getting issue with this default timeout . Hence we increased this timeout value to standard LE timeout i.e 20s. Kindly let us know, is there any timeout explicitly defined for the autoconnect in the spec. Thanks and regards, Mahesh Vithal Talewad -----Original Message----- From: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Sent: Wednesday, March 20, 2024 3:21 PM To: Mahesh Talewad <mahesh.talewad@nxp.com> Cc: linux-bluetooth@vger.kernel.org; Devyani Godbole <devyani.godbole@nxp.com>; Sarveshwar Bajaj <sarveshwar.bajaj@nxp.com> Subject: [EXT] Re: [PATCH BlueZ v1 1/1] LE Create Connection command timeout increased to 20 secs from 4 secs Caution: This is an external email. Please take care when clicking links or opening attachments. When in doubt, report the message using the 'Report this email' button Hi Mahesh, On Mon, Mar 18, 2024 at 12:37 PM Mahesh Talewad <mahesh.talewad@nxp.com> wrote: > > - As per specs LE Connection timeout is 20 secs but in implementation, > it was 4 secs. Hence increased this timeout to 20 Secs. > > Signed-off-by: Mahesh Talewad <mahesh.talewad@nxp.com> > --- > net/bluetooth/hci_event.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c > index 4ae224824012..06fe5f6b9546 100644 > --- a/net/bluetooth/hci_event.c > +++ b/net/bluetooth/hci_event.c > @@ -6067,7 +6067,7 @@ static struct hci_conn *check_pending_le_conn(struct hci_dev *hdev, > } > > conn = hci_connect_le(hdev, addr, addr_type, addr_resolved, > - BT_SECURITY_LOW, hdev->def_le_autoconnect_timeout, > + BT_SECURITY_LOW, HCI_LE_CONN_TIMEOUT, > HCI_ROLE_MASTER); > if (!IS_ERR(conn)) { > /* If HCI_AUTO_CONN_EXPLICIT is set, conn is already > owned > -- > 2.34.1 Afaik this is on purpose since it is the autoconnect procedure, rather than user initiate connection, so are you running into a problem if the timeout is different? -- Luiz Augusto von Dentz
Hi Mahesh, On Wed, Mar 20, 2024 at 10:56 AM Mahesh Talewad <mahesh.talewad@nxp.com> wrote: > > Hi Luiz, > > Yes, its auto connect scenario. > While running connect disconnect in a loop on one of the chip, we are getting issue with this default timeout . Hence we increased this timeout value to standard LE timeout i.e 20s. > Kindly let us know, is there any timeout explicitly defined for the autoconnect in the spec. What exactly is the issue though, or are you saying it is a controller issue because the attempts are too closely together when the timeout is just 4 seconds, note that you are just working around the problem because users can bypass the default when set via conn->conn_timeout. > Thanks and regards, > Mahesh Vithal Talewad > > -----Original Message----- > From: Luiz Augusto von Dentz <luiz.dentz@gmail.com> > Sent: Wednesday, March 20, 2024 3:21 PM > To: Mahesh Talewad <mahesh.talewad@nxp.com> > Cc: linux-bluetooth@vger.kernel.org; Devyani Godbole <devyani.godbole@nxp.com>; Sarveshwar Bajaj <sarveshwar.bajaj@nxp.com> > Subject: [EXT] Re: [PATCH BlueZ v1 1/1] LE Create Connection command timeout increased to 20 secs from 4 secs > > Caution: This is an external email. Please take care when clicking links or opening attachments. When in doubt, report the message using the 'Report this email' button > > > Hi Mahesh, > > On Mon, Mar 18, 2024 at 12:37 PM Mahesh Talewad <mahesh.talewad@nxp.com> wrote: > > > > - As per specs LE Connection timeout is 20 secs but in implementation, > > it was 4 secs. Hence increased this timeout to 20 Secs. > > > > Signed-off-by: Mahesh Talewad <mahesh.talewad@nxp.com> > > --- > > net/bluetooth/hci_event.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c > > index 4ae224824012..06fe5f6b9546 100644 > > --- a/net/bluetooth/hci_event.c > > +++ b/net/bluetooth/hci_event.c > > @@ -6067,7 +6067,7 @@ static struct hci_conn *check_pending_le_conn(struct hci_dev *hdev, > > } > > > > conn = hci_connect_le(hdev, addr, addr_type, addr_resolved, > > - BT_SECURITY_LOW, hdev->def_le_autoconnect_timeout, > > + BT_SECURITY_LOW, HCI_LE_CONN_TIMEOUT, > > HCI_ROLE_MASTER); > > if (!IS_ERR(conn)) { > > /* If HCI_AUTO_CONN_EXPLICIT is set, conn is already > > owned > > -- > > 2.34.1 > > Afaik this is on purpose since it is the autoconnect procedure, rather than user initiate connection, so are you running into a problem if the timeout is different? > > -- > Luiz Augusto von Dentz
Hi Luiz, On our DUT, we can see that the host issues create connection cancel command after 4-sec if there is no connection complete event for LE create connection cmd. As per core spec v5.3 section 7.8.5, advertisement interval range is - Advertising_Interval_Min Default : 0x0800(1.28s) Time Range: 20ms to 10.24s Advertising_Interval_Max Default : 0x0800(1.28s) Time Range: 20ms to 10.24s If the remote device is using adv interval of > 4 sec, it is difficult to make a connection with the current timeout value. Also, with the default interval of 1.28 sec, we will get only 3 chances to capture the adv packets with the 4 sec window. Hence we want to increase this timeout to 20sec. Note: In Android this timeout value is 29 secs. Does setting via 'conn->conn_timeout' mean setting 'Autoconnecttimeout=value' in main.conf file? Thanks and regards, Mahesh Vithal Talewad -----Original Message----- From: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Sent: Wednesday, March 20, 2024 5:13 PM To: Mahesh Talewad <mahesh.talewad@nxp.com> Cc: linux-bluetooth@vger.kernel.org; Devyani Godbole <devyani.godbole@nxp.com>; Sarveshwar Bajaj <sarveshwar.bajaj@nxp.com> Subject: Re: [EXT] Re: [PATCH BlueZ v1 1/1] LE Create Connection command timeout increased to 20 secs from 4 secs Caution: This is an external email. Please take care when clicking links or opening attachments. When in doubt, report the message using the 'Report this email' button Hi Mahesh, On Wed, Mar 20, 2024 at 10:56 AM Mahesh Talewad <mahesh.talewad@nxp.com> wrote: > > Hi Luiz, > > Yes, its auto connect scenario. > While running connect disconnect in a loop on one of the chip, we are getting issue with this default timeout . Hence we increased this timeout value to standard LE timeout i.e 20s. > Kindly let us know, is there any timeout explicitly defined for the autoconnect in the spec. What exactly is the issue though, or are you saying it is a controller issue because the attempts are too closely together when the timeout is just 4 seconds, note that you are just working around the problem because users can bypass the default when set via conn->conn_timeout. > Thanks and regards, > Mahesh Vithal Talewad > > -----Original Message----- > From: Luiz Augusto von Dentz <luiz.dentz@gmail.com> > Sent: Wednesday, March 20, 2024 3:21 PM > To: Mahesh Talewad <mahesh.talewad@nxp.com> > Cc: linux-bluetooth@vger.kernel.org; Devyani Godbole > <devyani.godbole@nxp.com>; Sarveshwar Bajaj <sarveshwar.bajaj@nxp.com> > Subject: [EXT] Re: [PATCH BlueZ v1 1/1] LE Create Connection command > timeout increased to 20 secs from 4 secs > > Caution: This is an external email. Please take care when clicking > links or opening attachments. When in doubt, report the message using > the 'Report this email' button > > > Hi Mahesh, > > On Mon, Mar 18, 2024 at 12:37 PM Mahesh Talewad <mahesh.talewad@nxp.com> wrote: > > > > - As per specs LE Connection timeout is 20 secs but in implementation, > > it was 4 secs. Hence increased this timeout to 20 Secs. > > > > Signed-off-by: Mahesh Talewad <mahesh.talewad@nxp.com> > > --- > > net/bluetooth/hci_event.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c > > index 4ae224824012..06fe5f6b9546 100644 > > --- a/net/bluetooth/hci_event.c > > +++ b/net/bluetooth/hci_event.c > > @@ -6067,7 +6067,7 @@ static struct hci_conn *check_pending_le_conn(struct hci_dev *hdev, > > } > > > > conn = hci_connect_le(hdev, addr, addr_type, addr_resolved, > > - BT_SECURITY_LOW, hdev->def_le_autoconnect_timeout, > > + BT_SECURITY_LOW, HCI_LE_CONN_TIMEOUT, > > HCI_ROLE_MASTER); > > if (!IS_ERR(conn)) { > > /* If HCI_AUTO_CONN_EXPLICIT is set, conn is already > > owned > > -- > > 2.34.1 > > Afaik this is on purpose since it is the autoconnect procedure, rather than user initiate connection, so are you running into a problem if the timeout is different? > > -- > Luiz Augusto von Dentz -- Luiz Augusto von Dentz
Hi Luiz, We tried with - 6093f28402aa6342890fc3adb6be355f804b719d - with this as well issue is observed. Thanks and regards, Mahesh Vithal Talewad -----Original Message----- From: Mahesh Talewad Sent: Monday, April 22, 2024 2:31 PM To: 'Luiz Augusto von Dentz' <luiz.dentz@gmail.com> Cc: linux-bluetooth@vger.kernel.org; Devyani Godbole <devyani.godbole@nxp.com>; Sarveshwar Bajaj <sarveshwar.bajaj@nxp.com> Subject: RE: [EXT] Re: [PATCH BlueZ v1 1/1] LE Create Connection command timeout increased to 20 secs from 4 secs Hi Luiz, On our DUT, we can see that the host issues create connection cancel command after 4-sec if there is no connection complete event for LE create connection cmd. As per core spec v5.3 section 7.8.5, advertisement interval range is - Advertising_Interval_Min Default : 0x0800(1.28s) Time Range: 20ms to 10.24s Advertising_Interval_Max Default : 0x0800(1.28s) Time Range: 20ms to 10.24s If the remote device is using adv interval of > 4 sec, it is difficult to make a connection with the current timeout value. Also, with the default interval of 1.28 sec, we will get only 3 chances to capture the adv packets with the 4 sec window. Hence we want to increase this timeout to 20sec. Note: In Android this timeout value is 29 secs. Does setting via 'conn->conn_timeout' mean setting 'Autoconnecttimeout=value' in main.conf file? Thanks and regards, Mahesh Vithal Talewad -----Original Message----- From: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Sent: Wednesday, March 20, 2024 5:13 PM To: Mahesh Talewad <mahesh.talewad@nxp.com> Cc: linux-bluetooth@vger.kernel.org; Devyani Godbole <devyani.godbole@nxp.com>; Sarveshwar Bajaj <sarveshwar.bajaj@nxp.com> Subject: Re: [EXT] Re: [PATCH BlueZ v1 1/1] LE Create Connection command timeout increased to 20 secs from 4 secs Caution: This is an external email. Please take care when clicking links or opening attachments. When in doubt, report the message using the 'Report this email' button Hi Mahesh, On Wed, Mar 20, 2024 at 10:56 AM Mahesh Talewad <mahesh.talewad@nxp.com> wrote: > > Hi Luiz, > > Yes, its auto connect scenario. > While running connect disconnect in a loop on one of the chip, we are getting issue with this default timeout . Hence we increased this timeout value to standard LE timeout i.e 20s. > Kindly let us know, is there any timeout explicitly defined for the autoconnect in the spec. What exactly is the issue though, or are you saying it is a controller issue because the attempts are too closely together when the timeout is just 4 seconds, note that you are just working around the problem because users can bypass the default when set via conn->conn_timeout. > Thanks and regards, > Mahesh Vithal Talewad > > -----Original Message----- > From: Luiz Augusto von Dentz <luiz.dentz@gmail.com> > Sent: Wednesday, March 20, 2024 3:21 PM > To: Mahesh Talewad <mahesh.talewad@nxp.com> > Cc: linux-bluetooth@vger.kernel.org; Devyani Godbole > <devyani.godbole@nxp.com>; Sarveshwar Bajaj <sarveshwar.bajaj@nxp.com> > Subject: [EXT] Re: [PATCH BlueZ v1 1/1] LE Create Connection command > timeout increased to 20 secs from 4 secs > > Caution: This is an external email. Please take care when clicking > links or opening attachments. When in doubt, report the message using > the 'Report this email' button > > > Hi Mahesh, > > On Mon, Mar 18, 2024 at 12:37 PM Mahesh Talewad <mahesh.talewad@nxp.com> wrote: > > > > - As per specs LE Connection timeout is 20 secs but in implementation, > > it was 4 secs. Hence increased this timeout to 20 Secs. > > > > Signed-off-by: Mahesh Talewad <mahesh.talewad@nxp.com> > > --- > > net/bluetooth/hci_event.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c > > index 4ae224824012..06fe5f6b9546 100644 > > --- a/net/bluetooth/hci_event.c > > +++ b/net/bluetooth/hci_event.c > > @@ -6067,7 +6067,7 @@ static struct hci_conn *check_pending_le_conn(struct hci_dev *hdev, > > } > > > > conn = hci_connect_le(hdev, addr, addr_type, addr_resolved, > > - BT_SECURITY_LOW, hdev->def_le_autoconnect_timeout, > > + BT_SECURITY_LOW, HCI_LE_CONN_TIMEOUT, > > HCI_ROLE_MASTER); > > if (!IS_ERR(conn)) { > > /* If HCI_AUTO_CONN_EXPLICIT is set, conn is already > > owned > > -- > > 2.34.1 > > Afaik this is on purpose since it is the autoconnect procedure, rather than user initiate connection, so are you running into a problem if the timeout is different? > > -- > Luiz Augusto von Dentz -- Luiz Augusto von Dentz
Hi Mahesh, On Wed, Apr 24, 2024 at 9:49 AM Mahesh Talewad <mahesh.talewad@nxp.com> wrote: > > Hi Luiz, > > We tried with - 6093f28402aa6342890fc3adb6be355f804b719d - with this as well issue is observed. The lets do something like: diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h index 5c12761cbc0e..fbf0a6263dae 100644 --- a/include/net/bluetooth/hci.h +++ b/include/net/bluetooth/hci.h @@ -456,7 +456,6 @@ enum { #define HCI_AUTO_OFF_TIMEOUT msecs_to_jiffies(2000) /* 2 seconds */ #define HCI_ACL_CONN_TIMEOUT msecs_to_jiffies(20000) /* 20 seconds */ #define HCI_LE_CONN_TIMEOUT msecs_to_jiffies(20000) /* 20 seconds */ -#define HCI_LE_AUTOCONN_TIMEOUT msecs_to_jiffies(4000) /* 4 seconds */ /* HCI data types */ #define HCI_COMMAND_PKT 0x01 diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 99b4e68075f4..651e5105fdd5 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2556,7 +2556,7 @@ struct hci_dev *hci_alloc_dev_priv(int sizeof_priv) hdev->le_rx_def_phys = HCI_LE_SET_PHY_1M; hdev->le_num_of_adv_sets = HCI_MAX_ADV_INSTANCES; hdev->def_multi_adv_rotation_duration = HCI_DEFAULT_ADV_DURATION; - hdev->def_le_autoconnect_timeout = HCI_LE_AUTOCONN_TIMEOUT; + hdev->def_le_autoconnect_timeout = HCI_LE_CONN_TIMEOUT; hdev->min_le_tx_power = HCI_TX_POWER_INVALID; hdev->max_le_tx_power = HCI_TX_POWER_INVALID;
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 4ae224824012..06fe5f6b9546 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -6067,7 +6067,7 @@ static struct hci_conn *check_pending_le_conn(struct hci_dev *hdev, } conn = hci_connect_le(hdev, addr, addr_type, addr_resolved, - BT_SECURITY_LOW, hdev->def_le_autoconnect_timeout, + BT_SECURITY_LOW, HCI_LE_CONN_TIMEOUT, HCI_ROLE_MASTER); if (!IS_ERR(conn)) { /* If HCI_AUTO_CONN_EXPLICIT is set, conn is already owned
- As per specs LE Connection timeout is 20 secs but in implementation, it was 4 secs. Hence increased this timeout to 20 Secs. Signed-off-by: Mahesh Talewad <mahesh.talewad@nxp.com> --- net/bluetooth/hci_event.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)