Hi Angela,
On Tue, Dec 21, 2021 at 07:17:43PM +0000, Angela Czubak wrote:
> If command & data registers are to be used and report ID >= 0xF
> use the sentinel value for report ID in the command.
> Do not alter the report ID itself as it needs to be inserted into the args
> buffer. If output register is to be used there is no need to insert
> report IDs >= 0xF.
OK, I see what you mean, but I believe that i2c_hid_set_or_send_report()
is the wrong place to implement this handling to begin with. How about a
modified version of your patch that I am pasting below (not tested)?
Thanks,
Dmitry
-- >8 -- >8 --
HID: i2c-hid: fix handling numbered reports with IDs of 15 and above
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 | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 517141138b00..9381a70b2948 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);
@@ -300,11 +307,6 @@ static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
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
