This patch series is an updated version of this one:
https://lore.kernel.org/all/[email protected]/
Changes since v3:
- Fixes for the kernel CI bot warnings
- We now do not miss NACK on the wakeup from the power saving mode
on the KVM installation reported by Enrik. For details, see
https://github.com/MichaelZaidman/hid-ft260/pull/7
Changes since v2:
- Remove SMBus Quick command support
- Missed NACK from big i2c read
- Wake up device from power saving mode
- Fix a NULL pointer dereference in ft260_i2c_write
- Missed NACK from busy device
Changes since v1:
- Do not populate hidraw device
- Avoid stale read buffer pointer
Michael Zaidman (13):
HID: ft260: ft260_xfer_status routine cleanup
HID: ft260: improve i2c write performance
HID: ft260: support i2c writes larger than HID report size
HID: ft260: support i2c reads greater than HID report size
HID: ft260: improve i2c large reads performance
HID: ft260: do not populate /dev/hidraw device
HID: ft260: skip unexpected HID input reports
HID: ft260: remove SMBus Quick command support
HID: ft260: missed NACK from big i2c read
HID: ft260: wake up device from power saving mode
HID: ft260: fix a NULL pointer dereference in ft260_i2c_write
HID: ft260: missed NACK from busy device
HID: ft260: fix sparse warnings
drivers/hid/hid-ft260.c | 325 +++++++++++++++++++++++-----------------
1 file changed, 191 insertions(+), 134 deletions(-)
--
2.34.1
The i2cdetect uses the SMBus Quick command by default to scan devices
on the I2C bus. The FT260 implements an I2C bus controller. The SMBus
is derived from I2C, but there are several differences between the
specifications of the two buses in the areas of timing, protocols,
operation modes, and electrical characteristics.
One of the differences is that the I2C devices allow the slave not
to ACK its slave address, but SMBus requires it to always ACK it as
a mechanism to detect a detachable device’s presence on the bus.
Since FT260 is the I2C bus controller, it does not acknowledge the
SMBus Quick write command, which sends a single bit to the device at
the place of the RD/WR bit.
The ft260 driver attempted to mimic the SMBus Quick Write functionality
by writing a single byte as the SMBus Byte Write command does.
Usually, one byte in the SMBus Quick Write will be fine. However, it may
cause problems with devices with a control register at offset 0, like
i2c muxes, for example, when scanned with the i2cdetect utility.
The i2cdetect with the "-r" option uses the SMBus Read Byte command,
which is a reasonable workaround. To prevent the I2C bus from locking
at write-only devices (most notably clock chips at address 0x69), use
the "-r" option in conjunction with scanning range parameters.
This patch removes the SMBus Quick command support.
$ sudo i2cdetect -y 13
Warning: Can't use SMBus Quick Write command, will skip some addresses
0 1 2 3 4 5 6 7 8 9 a b c d e f
00:
10:
20:
30: -- -- -- -- -- -- -- --
40:
50: 50 51 -- -- -- -- -- -- -- -- -- -- -- -- -- --
60:
70:
$ sudo i2cdetect -y -r 13
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: 50 51 -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
Reported-by: Vince Asbridge <[email protected]>
Reported-by: Stephen Shirron <[email protected]>
Reported-by: Enrik Berkhan <[email protected]>
Signed-off-by: Michael Zaidman <[email protected]>
---
drivers/hid/hid-ft260.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index 8b6ebc5228eb..d186aa5a8e73 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -630,14 +630,6 @@ static int ft260_smbus_xfer(struct i2c_adapter *adapter, u16 addr, u16 flags,
}
switch (size) {
- case I2C_SMBUS_QUICK:
- if (read_write == I2C_SMBUS_READ)
- ret = ft260_i2c_read(dev, addr, &data->byte, 0,
- FT260_FLAG_START_STOP);
- else
- ret = ft260_smbus_write(dev, addr, cmd, NULL, 0,
- FT260_FLAG_START_STOP);
- break;
case I2C_SMBUS_BYTE:
if (read_write == I2C_SMBUS_READ)
ret = ft260_i2c_read(dev, addr, &data->byte, 1,
@@ -720,7 +712,7 @@ static int ft260_smbus_xfer(struct i2c_adapter *adapter, u16 addr, u16 flags,
static u32 ft260_functionality(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_QUICK |
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_I2C_BLOCK;
}
--
2.34.1
The FT260 is not supposed to generate unexpected HID reports. However,
in theory, the unsolicited HID Input reports can be issued by a specially
crafted malicious USB device masquerading as FT260 when the attacker has
physical access to the USB port. In this case, the read_buf pointer points
to the final data portion of the previous I2C Read transfer, and the memcpy
invoked in the ft260_raw_event() will try copying the content of the
unexpected report into the wrong location.
This commit sets the Read buffer pointer to NULL on the I2C Read
transaction completion and checks it in the ft260_raw_event() to detect
and skip the unsolicited Input report.
Reported-by: Enrik Berkhan <[email protected]>
Signed-off-by: Michael Zaidman <[email protected]>
---
drivers/hid/hid-ft260.c | 36 ++++++++++++++++++++++++------------
1 file changed, 24 insertions(+), 12 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index 8d6d2a19b9ed..8b6ebc5228eb 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -464,7 +464,7 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data,
u16 len, u8 flag)
{
u16 rd_len;
- int timeout, ret;
+ int timeout, ret = 0;
struct ft260_i2c_read_request_report rep;
struct hid_device *hdev = dev->hdev;
@@ -480,10 +480,6 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data,
rd_len = FT260_RD_DATA_MAX;
}
- dev->read_idx = 0;
- dev->read_buf = data;
- dev->read_len = rd_len;
-
rep.report = FT260_I2C_READ_REQ;
rep.length = cpu_to_le16(rd_len);
rep.address = addr;
@@ -494,22 +490,30 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data,
reinit_completion(&dev->wait);
+ dev->read_idx = 0;
+ dev->read_buf = data;
+ dev->read_len = rd_len;
+
ret = ft260_hid_output_report(hdev, (u8 *)&rep, sizeof(rep));
if (ret < 0) {
hid_err(hdev, "%s: failed with %d\n", __func__, ret);
- return ret;
+ goto ft260_i2c_read_exit;
}
timeout = msecs_to_jiffies(5000);
if (!wait_for_completion_timeout(&dev->wait, timeout)) {
+ ret = -ETIMEDOUT;
ft260_i2c_reset(hdev);
- return -ETIMEDOUT;
+ goto ft260_i2c_read_exit;
}
+ dev->read_buf = NULL;
+
ret = ft260_xfer_status(dev);
if (ret < 0) {
+ ret = -EIO;
ft260_i2c_reset(hdev);
- return -EIO;
+ goto ft260_i2c_read_exit;
}
len -= rd_len;
@@ -518,7 +522,9 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data,
} while (len > 0);
- return 0;
+ft260_i2c_read_exit:
+ dev->read_buf = NULL;
+ return ret;
}
/*
@@ -1036,6 +1042,13 @@ static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report,
ft260_dbg("i2c resp: rep %#02x len %d\n", xfer->report,
xfer->length);
+ if ((dev->read_buf == NULL) ||
+ (xfer->length > dev->read_len - dev->read_idx)) {
+ hid_err(hdev, "unexpected report %#02x, length %d\n",
+ xfer->report, xfer->length);
+ return -1;
+ }
+
memcpy(&dev->read_buf[dev->read_idx], &xfer->data,
xfer->length);
dev->read_idx += xfer->length;
@@ -1044,10 +1057,9 @@ static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report,
complete(&dev->wait);
} else {
- hid_err(hdev, "unknown report: %#02x\n", xfer->report);
- return 0;
+ hid_err(hdev, "unhandled report %#02x\n", xfer->report);
}
- return 1;
+ return 0;
}
static struct hid_driver ft260_driver = {
--
2.34.1
The patch increases the read buffer size to 180 bytes. It reduces
the number of ft260_i2c_read() calls by three, improving the big
reads performance.
$ sudo i2ctransfer -y -f 13 w2@0x51 0x0 0x0 r180
Before:
[ +4.071878] ft260_i2c_write_read: off 0x0 rlen 180 wlen 2
[ +0.000005] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0
[ +0.001097] ft260_xfer_status: bus_status 0x41, clock 100
[ +0.000175] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000004] ft260_i2c_read: rep 0xc2 addr 0x51 len 180 rlen 60 flag 0x3
[ +0.008579] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.000208] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 120 rlen 60 flag 0x0
[ +0.008794] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.000181] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 60 rlen 60 flag 0x4
[ +0.008817] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.000223] ft260_xfer_status: bus_status 0x20, clock 100
After:
[ +11.611642] ft260_i2c_write_read: off 0x0 rlen 180 wlen 2
[ +0.000005] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0
[ +0.008001] ft260_xfer_status: bus_status 0x20, clock 100
[ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 180 rlen 180 flag 0x7
[ +0.008994] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.007987] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.007992] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.000206] ft260_xfer_status: bus_status 0x20, clock 100
Suggested-by: Enrik Berkhan <[email protected]>
Signed-off-by: Michael Zaidman <[email protected]>
---
drivers/hid/hid-ft260.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index a354089bb747..91f9087e49dc 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -30,12 +30,19 @@ MODULE_PARM_DESC(debug, "Toggle FT260 debugging messages");
#define FT260_REPORT_MAX_LENGTH (64)
#define FT260_I2C_DATA_REPORT_ID(len) (FT260_I2C_REPORT_MIN + (len - 1) / 4)
+
/*
- * The input report format assigns 62 bytes for the data payload, but ft260
- * returns 60 and 2 in two separate transactions. To minimize transfer time
- * in reading chunks mode, set the maximum read payload length to 60 bytes.
- */
-#define FT260_RD_DATA_MAX (60)
+ * The ft260 input report format defines 62 bytes for the data payload, but
+ * when requested 62 bytes, the controller returns 60 and 2 in separate input
+ * reports. To achieve better performance with the multi-report read data
+ * transfers, we set the maximum read payload length to a multiple of 60.
+ * With a 100 kHz I2C clock, one 240 bytes read takes about 1/27 second,
+ * which is excessive; On the other hand, some higher layer drivers like at24
+ * or optoe limit the i2c reads to 128 bytes. To not block other drivers out
+ * of I2C for potentially troublesome amounts of time, we select the maximum
+ * read payload length to be 180 bytes.
+*/
+#define FT260_RD_DATA_MAX (180)
#define FT260_WR_DATA_MAX (60)
/*
--
2.34.1
The FT260 controller does not return NACK when performing a big
read (of multiple hid reports size) from a non-existing device
or from the device responding with NACK when it is not ready
to serve the request. However, it responds correctly with NACK
to a read of up to a single hid report size.
To overcome this issue, we split the muli-report read request
into a read of a single HID report of 60 bytes size and a
multi-report read.
Big read of 256 bytes with first read of 60 bytes:
$ sudo ./i2cperf -d 2 -o 2 -s 256 -r 0-0xff 1 0x50 -S
[ +5.633280] ft260_i2c_write_read: off 0x0 rlen 255 wlen 2
[ +0.000006] ft260_i2c_write: rep 0xd0 addr 0x50 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0
[ +0.013205] ft260_xfer_status: bus_status 0x20, clock 100
[ +0.000007] ft260_i2c_read: rep 0xc2 addr 0x50 len 255 rlen 60 flag 0x3
[ +0.010932] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.004733] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000006] ft260_i2c_read: rep 0xc2 addr 0x50 len 195 rlen 128 flag 0x0
[ +0.012572] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.005789] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.003189] ft260_raw_event: i2c resp: rep 0xd1 len 8
[ +0.004092] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000010] ft260_i2c_read: rep 0xc2 addr 0x50 len 67 rlen 67 flag 0x4
[ +0.011688] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.004700] ft260_raw_event: i2c resp: rep 0xd1 len 7
[ +0.004858] ft260_xfer_status: bus_status 0x20, clock 100
Read from non-existing device at address 8. The first 60 read responded
with NACK.
$ sudo ./i2cperf -d 2 -o 2 -s 256 -r 0-0xff 1 0x8 -S
[Oct19 15:37] ft260_i2c_write_read: off 0x0 rlen 255 wlen 2
[ +0.000007] ft260_i2c_write: rep 0xd0 addr 0x8 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0
[ +0.022820] ft260_xfer_status: bus_status 0x20, clock 100
[ +0.000007] ft260_i2c_read: rep 0xc2 addr 0x8 len 255 rlen 60 flag 0x3
[ +0.010658] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.005965] ft260_xfer_status: bus_status 0x46, clock 100 <-- NACK
[ +0.000009] ft260 0003:0403:6030.0004: i2c bus error: 0x46
[ +0.007784] ft260_i2c_reset: done
Co-developed-by: Enrik Berkhan <[email protected]>
Signed-off-by: Enrik Berkhan <[email protected]>
Signed-off-by: Michael Zaidman <[email protected]>
---
drivers/hid/hid-ft260.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index d186aa5a8e73..40fae81386e3 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -464,6 +464,7 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data,
u16 len, u8 flag)
{
u16 rd_len;
+ u16 rd_data_max = 60;
int timeout, ret = 0;
struct ft260_i2c_read_request_report rep;
struct hid_device *hdev = dev->hdev;
@@ -473,12 +474,13 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data,
else
flag = FT260_FLAG_START;
do {
- if (len <= FT260_RD_DATA_MAX) {
+ if (len <= rd_data_max) {
rd_len = len;
flag |= FT260_FLAG_STOP;
} else {
- rd_len = FT260_RD_DATA_MAX;
+ rd_len = rd_data_max;
}
+ rd_data_max = FT260_RD_DATA_MAX;
rep.report = FT260_I2C_READ_REQ;
rep.length = cpu_to_le16(rd_len);
--
2.34.1
After clarifying with FTDI's support, it turned out that the error
condition (bit 1) in byte 1 of the i2c status HID report is a status
bit reflecting all error conditions. When bits 2, 3, or 4 are raised
to 1, bit 1 is set to 1 also. Since the ft260_xfer_status routine tests
the error condition bit and exits in the case of an error, the program
flow never reaches the conditional expressions for 2, 3, and 4 bits when
any of them indicates an error state. Though these expressions are never
evaluated to true, they are checked several times per IO, increasing the
ft260_xfer_status polling cycle duration.
The patch removes the conditional expressions for 2, 3, and 4 bits in
byte 1 of the i2c status HID report.
Signed-off-by: Michael Zaidman <[email protected]>
Tested-by: Guillaume Champagne <[email protected]>
---
drivers/hid/hid-ft260.c | 30 ++++++++++--------------------
1 file changed, 10 insertions(+), 20 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index 79505c64dbfe..a35201d68b15 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -313,27 +313,17 @@ static int ft260_xfer_status(struct ft260_device *dev)
if (report.bus_status & FT260_I2C_STATUS_CTRL_BUSY)
return -EAGAIN;
- if (report.bus_status & FT260_I2C_STATUS_BUS_BUSY)
- return -EBUSY;
-
- if (report.bus_status & FT260_I2C_STATUS_ERROR)
+ /*
+ * The error condition (bit 1) is a status bit reflecting any
+ * error conditions. When any of the bits 2, 3, or 4 are raised
+ * to 1, bit 1 is also set to 1.
+ */
+ if (report.bus_status & FT260_I2C_STATUS_ERROR) {
+ hid_err(hdev, "i2c bus error: %#02x\n", report.bus_status);
return -EIO;
+ }
- ret = -EIO;
-
- if (report.bus_status & FT260_I2C_STATUS_ADDR_NO_ACK)
- ft260_dbg("unacknowledged address\n");
-
- if (report.bus_status & FT260_I2C_STATUS_DATA_NO_ACK)
- ft260_dbg("unacknowledged data\n");
-
- if (report.bus_status & FT260_I2C_STATUS_ARBITR_LOST)
- ft260_dbg("arbitration loss\n");
-
- if (report.bus_status & FT260_I2C_STATUS_CTRL_IDLE)
- ret = 0;
-
- return ret;
+ return 0;
}
static int ft260_hid_output_report(struct hid_device *hdev, u8 *data,
@@ -376,7 +366,7 @@ static int ft260_hid_output_report_check_status(struct ft260_device *dev,
break;
} while (--try);
- if (ret == 0 || ret == -EBUSY)
+ if (ret == 0)
return 0;
ft260_i2c_reset(hdev);
--
2.34.1
A random i2c read operation in EEPROM devices is implemented as a dummy
write operation, followed by a current address read operation. The dummy
write operation is used to load the target byte or word address (a.k.a
offset) into the offset counter, from which the subsequent read operation
then reads.
To support longer than one HID report size random read, the ft260 driver
issues multiple pairs of i2c write offset + read data transactions of HID
report size so that the EEPROM device sees many i2c random read requests
from different offsets.
Two issues with the current implementation:
- This approach suffers from extra overhead caused by writing offset
requests.
- Necessity to handle offset per HID report in big-endian representation
as EEPROM devices expect. The current implementation does not do it and
correctly handles the reads up to 60 bytes only.
This patch addresses both issues by implementing more efficient approach.
It issues a single i2c read request of up to the EEPROM page size and then
waits for the data to arrive in multiple HID reports. For example, to read
the 256 bytes from a 24LC512 chip, which has 128 bytes page size, the old
method performs six ft260_i2c_write_read transactions while the new - two
only.
Before:
$ sudo ./i2cperf -d 2 -o 2 -s 128 -r 0-0xff 13 0x51 -S
Read block via i2ctransfer by chunks
-------------------------------------------------------------------
data rate(bps) efficiency(%) data size(B) total IOs IO size(B)
-------------------------------------------------------------------
40803 85 256 2 128
Kernel log of a single 128 bytes read request:
[ +2.376308] ft260_i2c_write_read: read_off 0x0 left_len 128 len 60
[ +0.000002] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0
[ +0.000707] ft260_xfer_status: bus_status 0x41, clock 100
[ +0.000173] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 60
[ +0.008660] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.000156] ft260_xfer_status: bus_status 0x20, clock 100
[ +0.000001] ft260_i2c_write_read: read_off 0x3c left_len 68 len 60
[ +0.000001] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x3c
[ +0.001034] ft260_xfer_status: bus_status 0x41, clock 100
[ +0.000191] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 60
[ +0.008614] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.000203] ft260_xfer_status: bus_status 0x20, clock 100
[ +0.000001] ft260_i2c_write_read: read_off 0x78 left_len 8 len 8
[ +0.000001] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x78
[ +0.000987] ft260_xfer_status: bus_status 0x41, clock 100
[ +0.000192] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 8
[ +0.002614] ft260_raw_event: i2c resp: rep 0xd1 len 8
[ +0.000200] ft260_xfer_status: bus_status 0x20, clock 100
After:
$ sudo ./i2cperf -d 2 -o 2 -s 128 -r 0-0xff 13 0x51 -S
Read block via i2ctransfer by chunks
-------------------------------------------------------------------
data rate(bps) efficiency(%) data size(B) total IOs IO size(B)
-------------------------------------------------------------------
43990 85 256 2 128
Kernel log of a single 128 bytes read request:
[ +1.464346] ft260_i2c_write_read: off 0x0 rlen 128 wlen 2
[ +0.000002] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0
[ +0.001653] ft260_xfer_status: bus_status 0x41, clock 100
[ +0.000188] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 128 rlen 60 flag 0x3
[ +0.008609] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.000157] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 68 rlen 60 flag 0x0
[ +0.008840] ft260_raw_event: i2c resp: rep 0xde len 60
[ +0.000203] ft260_xfer_status: bus_status 0x40, clock 100
[ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 8 rlen 8 flag 0x4
[ +0.002794] ft260_raw_event: i2c resp: rep 0xd1 len 8
[ +0.000201] ft260_xfer_status: bus_status 0x20, clock 100
Signed-off-by: Michael Zaidman <[email protected]>
Tested-by: Guillaume Champagne <[email protected]>
---
drivers/hid/hid-ft260.c | 127 +++++++++++++++++++++-------------------
1 file changed, 66 insertions(+), 61 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index cec83f69ebdc..a354089bb747 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -456,49 +456,62 @@ static int ft260_smbus_write(struct ft260_device *dev, u8 addr, u8 cmd,
static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data,
u16 len, u8 flag)
{
+ u16 rd_len;
+ int timeout, ret;
struct ft260_i2c_read_request_report rep;
struct hid_device *hdev = dev->hdev;
- int timeout;
- int ret;
- if (len > FT260_RD_DATA_MAX) {
- hid_err(hdev, "%s: unsupported rd len: %d\n", __func__, len);
- return -EINVAL;
- }
+ if ((flag & FT260_FLAG_START_REPEATED) == FT260_FLAG_START_REPEATED)
+ flag = FT260_FLAG_START_REPEATED;
+ else
+ flag = FT260_FLAG_START;
+ do {
+ if (len <= FT260_RD_DATA_MAX) {
+ rd_len = len;
+ flag |= FT260_FLAG_STOP;
+ } else {
+ rd_len = FT260_RD_DATA_MAX;
+ }
- dev->read_idx = 0;
- dev->read_buf = data;
- dev->read_len = len;
+ dev->read_idx = 0;
+ dev->read_buf = data;
+ dev->read_len = rd_len;
- rep.report = FT260_I2C_READ_REQ;
- rep.length = cpu_to_le16(len);
- rep.address = addr;
- rep.flag = flag;
+ rep.report = FT260_I2C_READ_REQ;
+ rep.length = cpu_to_le16(rd_len);
+ rep.address = addr;
+ rep.flag = flag;
- ft260_dbg("rep %#02x addr %#02x len %d\n", rep.report, rep.address,
- rep.length);
+ ft260_dbg("rep %#02x addr %#02x len %d rlen %d flag %#x\n",
+ rep.report, rep.address, len, rd_len, flag);
- reinit_completion(&dev->wait);
+ reinit_completion(&dev->wait);
- ret = ft260_hid_output_report(hdev, (u8 *)&rep, sizeof(rep));
- if (ret < 0) {
- hid_err(hdev, "%s: failed to start transaction, ret %d\n",
- __func__, ret);
- return ret;
- }
+ ret = ft260_hid_output_report(hdev, (u8 *)&rep, sizeof(rep));
+ if (ret < 0) {
+ hid_err(hdev, "%s: failed with %d\n", __func__, ret);
+ return ret;
+ }
- timeout = msecs_to_jiffies(5000);
- if (!wait_for_completion_timeout(&dev->wait, timeout)) {
- ft260_i2c_reset(hdev);
- return -ETIMEDOUT;
- }
+ timeout = msecs_to_jiffies(5000);
+ if (!wait_for_completion_timeout(&dev->wait, timeout)) {
+ ft260_i2c_reset(hdev);
+ return -ETIMEDOUT;
+ }
- ret = ft260_xfer_status(dev);
- if (ret == 0)
- return 0;
+ ret = ft260_xfer_status(dev);
+ if (ret < 0) {
+ ft260_i2c_reset(hdev);
+ return -EIO;
+ }
- ft260_i2c_reset(hdev);
- return -EIO;
+ len -= rd_len;
+ data += rd_len;
+ flag = 0;
+
+ } while (len > 0);
+
+ return 0;
}
/*
@@ -509,45 +522,37 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data,
*/
static int ft260_i2c_write_read(struct ft260_device *dev, struct i2c_msg *msgs)
{
- int len, ret;
- u16 left_len = msgs[1].len;
- u8 *read_buf = msgs[1].buf;
+ int ret;
+ int wr_len = msgs[0].len;
+ int rd_len = msgs[1].len;
+ struct hid_device *hdev = dev->hdev;
u8 addr = msgs[0].addr;
u16 read_off = 0;
- struct hid_device *hdev = dev->hdev;
- if (msgs[0].len > 2) {
- hid_err(hdev, "%s: unsupported wr len: %d\n", __func__,
- msgs[0].len);
+ if (wr_len > 2) {
+ hid_err(hdev, "%s: invalid wr_len: %d\n", __func__, wr_len);
return -EOPNOTSUPP;
}
- memcpy(&read_off, msgs[0].buf, msgs[0].len);
-
- do {
- if (left_len <= FT260_RD_DATA_MAX)
- len = left_len;
+ if (ft260_debug) {
+ if (wr_len == 2)
+ read_off = be16_to_cpu(*(u16 *)msgs[0].buf);
else
- len = FT260_RD_DATA_MAX;
+ read_off = *msgs[0].buf;
- ft260_dbg("read_off %#x left_len %d len %d\n", read_off,
- left_len, len);
-
- ret = ft260_i2c_write(dev, addr, (u8 *)&read_off, msgs[0].len,
- FT260_FLAG_START);
- if (ret < 0)
- return ret;
-
- ret = ft260_i2c_read(dev, addr, read_buf, len,
- FT260_FLAG_START_STOP);
- if (ret < 0)
- return ret;
+ pr_info("%s: off %#x rlen %d wlen %d\n", __func__,
+ read_off, rd_len, wr_len);
+ }
- left_len -= len;
- read_buf += len;
- read_off += len;
+ ret = ft260_i2c_write(dev, addr, msgs[0].buf, wr_len,
+ FT260_FLAG_START);
+ if (ret < 0)
+ return ret;
- } while (left_len > 0);
+ ret = ft260_i2c_read(dev, addr, msgs[1].buf, rd_len,
+ FT260_FLAG_START_STOP_REPEATED);
+ if (ret < 0)
+ return ret;
return 0;
}
--
2.34.1
The FT260 can enter a power saving mode after being idle for longer
than 5 seconds.
When being woken up from power saving mode by an I2C write request,
a possible NACK is not correctly reported by the controller. As a
workaround, the driver will issue an I2C status report two times in
ft260_xfer_status() after the chip has been idle for more than 5s.
Co-developed-by: Enrik Berkhan <[email protected]>
Signed-off-by: Enrik Berkhan <[email protected]>
Signed-off-by: Michael Zaidman <[email protected]>
---
drivers/hid/hid-ft260.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index 40fae81386e3..ac133980dfe9 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -31,6 +31,8 @@ MODULE_PARM_DESC(debug, "Toggle FT260 debugging messages");
#define FT260_REPORT_MAX_LENGTH (64)
#define FT260_I2C_DATA_REPORT_ID(len) (FT260_I2C_REPORT_MIN + (len - 1) / 4)
+#define FT260_WAKEUP_NEEDED_AFTER_MS (4800) /* 5s minus 200ms margin */
+
/*
* The ft260 input report format defines 62 bytes for the data payload, but
* when requested 62 bytes, the controller returns 60 and 2 in separate input
@@ -237,6 +239,7 @@ struct ft260_device {
struct completion wait;
struct mutex lock;
u8 write_buf[FT260_REPORT_MAX_LENGTH];
+ unsigned long need_wakeup_at;
u8 *read_buf;
u16 read_idx;
u16 read_len;
@@ -306,6 +309,20 @@ static int ft260_xfer_status(struct ft260_device *dev)
struct ft260_get_i2c_status_report report;
int ret;
+ if (time_is_before_jiffies(dev->need_wakeup_at)) {
+ ret = ft260_hid_feature_report_get(hdev, FT260_I2C_STATUS,
+ (u8 *)&report, sizeof(report));
+ if (unlikely(ret < 0)) {
+ hid_err(hdev, "failed to retrieve status: %d, no wakeup\n",
+ ret);
+ } else {
+ dev->need_wakeup_at = jiffies +
+ msecs_to_jiffies(FT260_WAKEUP_NEEDED_AFTER_MS);
+ ft260_dbg("bus_status %#02x, wakeup\n",
+ report.bus_status);
+ }
+ }
+
ret = ft260_hid_feature_report_get(hdev, FT260_I2C_STATUS,
(u8 *)&report, sizeof(report));
if (unlikely(ret < 0)) {
--
2.34.1
Fix 'cast to restricted' sparse warnings reported by kernel test robot
in https://lore.kernel.org/all/[email protected]/
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Michael Zaidman <[email protected]>
---
drivers/hid/hid-ft260.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index d5b092b85d7f..333341e80b0e 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -588,7 +588,7 @@ static int ft260_i2c_write_read(struct ft260_device *dev, struct i2c_msg *msgs)
if (ft260_debug) {
if (wr_len == 2)
- read_off = be16_to_cpu(*(u16 *)msgs[0].buf);
+ read_off = be16_to_cpu(*(__be16 *)msgs[0].buf);
else
read_off = *msgs[0].buf;
@@ -830,7 +830,7 @@ static int ft260_byte_show(struct hid_device *hdev, int id, u8 *cfg, int len,
}
static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len,
- u16 *field, u8 *buf)
+ __le16 *field, u8 *buf)
{
int ret;
@@ -859,9 +859,9 @@ static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len,
#define FT260_I2CST_ATTR_SHOW(name) \
FT260_ATTR_SHOW(name, ft260_get_i2c_status_report, \
- FT260_I2C_STATUS, u16, ft260_word_show)
+ FT260_I2C_STATUS, __le16, ft260_word_show)
-#define FT260_ATTR_STORE(name, reptype, id, req, type, func) \
+#define FT260_ATTR_STORE(name, reptype, id, req, type, ctype, func) \
static ssize_t name##_store(struct device *kdev, \
struct device_attribute *attr, \
const char *buf, size_t count) \
@@ -871,7 +871,7 @@ static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len,
type name; \
int ret; \
\
- if (!func(buf, 10, &name)) { \
+ if (!func(buf, 10, (ctype *)&name)) { \
rep.name = name; \
rep.report = id; \
rep.request = req; \
@@ -887,11 +887,11 @@ static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len,
#define FT260_BYTE_ATTR_STORE(name, reptype, req) \
FT260_ATTR_STORE(name, reptype, FT260_SYSTEM_SETTINGS, req, \
- u8, kstrtou8)
+ u8, u8, kstrtou8)
#define FT260_WORD_ATTR_STORE(name, reptype, req) \
FT260_ATTR_STORE(name, reptype, FT260_SYSTEM_SETTINGS, req, \
- u16, kstrtou16)
+ __le16, u16, kstrtou16)
FT260_SSTAT_ATTR_SHOW(chip_mode);
static DEVICE_ATTR_RO(chip_mode);
--
2.34.1
On Sat, 5 Nov 2022, Michael Zaidman wrote:
> This patch series is an updated version of this one:
> https://lore.kernel.org/all/[email protected]/
>
> Changes since v3:
> - Fixes for the kernel CI bot warnings
> - We now do not miss NACK on the wakeup from the power saving mode
> on the KVM installation reported by Enrik. For details, see
> https://github.com/MichaelZaidman/hid-ft260/pull/7
>
> Changes since v2:
>
> - Remove SMBus Quick command support
> - Missed NACK from big i2c read
> - Wake up device from power saving mode
> - Fix a NULL pointer dereference in ft260_i2c_write
> - Missed NACK from busy device
>
> Changes since v1:
>
> - Do not populate hidraw device
> - Avoid stale read buffer pointer
>
> Michael Zaidman (13):
> HID: ft260: ft260_xfer_status routine cleanup
> HID: ft260: improve i2c write performance
> HID: ft260: support i2c writes larger than HID report size
> HID: ft260: support i2c reads greater than HID report size
> HID: ft260: improve i2c large reads performance
> HID: ft260: do not populate /dev/hidraw device
> HID: ft260: skip unexpected HID input reports
> HID: ft260: remove SMBus Quick command support
> HID: ft260: missed NACK from big i2c read
> HID: ft260: wake up device from power saving mode
> HID: ft260: fix a NULL pointer dereference in ft260_i2c_write
> HID: ft260: missed NACK from busy device
> HID: ft260: fix sparse warnings
Hi Michael,
this is now queued in hid.git#for-6.2/ft260.
Thanks,
--
Jiri Kosina
SUSE Labs
On Fri, Nov 11, 2022 at 11:19:32AM +0100, Jiri Kosina wrote:
> On Sat, 5 Nov 2022, Michael Zaidman wrote:
>
> > This patch series is an updated version of this one:
> > https://lore.kernel.org/all/[email protected]/
> >
> > Changes since v3:
> > - Fixes for the kernel CI bot warnings
> > - We now do not miss NACK on the wakeup from the power saving mode
> > on the KVM installation reported by Enrik. For details, see
> > https://github.com/MichaelZaidman/hid-ft260/pull/7
> >
> > Changes since v2:
> >
> > - Remove SMBus Quick command support
> > - Missed NACK from big i2c read
> > - Wake up device from power saving mode
> > - Fix a NULL pointer dereference in ft260_i2c_write
> > - Missed NACK from busy device
> >
> > Changes since v1:
> >
> > - Do not populate hidraw device
> > - Avoid stale read buffer pointer
> >
> > Michael Zaidman (13):
> > HID: ft260: ft260_xfer_status routine cleanup
> > HID: ft260: improve i2c write performance
> > HID: ft260: support i2c writes larger than HID report size
> > HID: ft260: support i2c reads greater than HID report size
> > HID: ft260: improve i2c large reads performance
> > HID: ft260: do not populate /dev/hidraw device
> > HID: ft260: skip unexpected HID input reports
> > HID: ft260: remove SMBus Quick command support
> > HID: ft260: missed NACK from big i2c read
> > HID: ft260: wake up device from power saving mode
> > HID: ft260: fix a NULL pointer dereference in ft260_i2c_write
> > HID: ft260: missed NACK from busy device
> > HID: ft260: fix sparse warnings
>
> Hi Michael,
>
> this is now queued in hid.git#for-6.2/ft260.
>
> Thanks,
>
> --
> Jiri Kosina
> SUSE Labs
>
Thanks, Jiri! Much appreciated.
Michael