[PATCH 01/12] HID: i2c-hid: fix handling numbered reports with IDs of 15 and above

From: Dmitry Torokhov
Date: Tue Jan 18 2022 - 02:26:38 EST


From: Angela Czubak <acz@xxxxxxxxxxxx>

Special handling of numbered reports with IDs of 15 and above is only
needed when executing what HID-I2C spec is calling "Class Specific
Requests", and not when simply sending output reports.

Additionally, our mangling of report ID in i2c_hid_set_or_send_report()
resulted in incorrect report ID being written into SET_REPORT command
payload.

To solve it let's move all the report ID manipulation into
__i2c_hid_command() where we form the command data structure.

Signed-off-by: Angela Czubak <acz@xxxxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/hid/i2c-hid/i2c-hid-core.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 517141138b00..bd7b0eeca3ea 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -97,6 +97,7 @@ union command {
__le16 reg;
__u8 reportTypeID;
__u8 opcode;
+ __u8 reportID;
} __packed c;
};

@@ -232,7 +233,13 @@ static int __i2c_hid_command(struct i2c_client *client,

if (length > 2) {
cmd->c.opcode = command->opcode;
- cmd->c.reportTypeID = reportID | reportType << 4;
+ if (reportID < 0x0F) {
+ cmd->c.reportTypeID = reportType << 4 | reportID;
+ } else {
+ cmd->c.reportTypeID = reportType << 4 | 0x0F;
+ cmd->c.reportID = reportID;
+ length++;
+ }
}

memcpy(cmd->data + length, args, args_len);
@@ -293,18 +300,13 @@ static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
u8 reportID, unsigned char *buf_recv, int data_len)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
- u8 args[3];
+ u8 args[2];
int ret;
int args_len = 0;
u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);

i2c_hid_dbg(ihid, "%s\n", __func__);

- if (reportID >= 0x0F) {
- args[args_len++] = reportID;
- reportID = 0x0F;
- }
-
args[args_len++] = readRegister & 0xFF;
args[args_len++] = readRegister >> 8;

@@ -350,18 +352,12 @@ static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
size = 2 /* size */ +
(reportID ? 1 : 0) /* reportID */ +
data_len /* buf */;
- args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
- 2 /* dataRegister */ +
+ args_len = 2 /* dataRegister */ +
size /* args */;

if (!use_data && maxOutputLength == 0)
return -ENOSYS;

- if (reportID >= 0x0F) {
- args[index++] = reportID;
- reportID = 0x0F;
- }
-
/*
* use the data register for feature reports or if the device does not
* support the output register
--
2.34.1.703.g22d0c6ccf7-goog