| From 9c9747f67a6ad86ecf23484a2d0cf92dd86d6f38 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 6 Feb 2026 17:32:58 +0100 |
| Subject: HID: mcp2221: cancel last I2C command on read error |
| |
| From: Romain Sioen <romain.sioen@microchip.com> |
| |
| [ Upstream commit e31b556c0ba21f20c298aa61181b96541140b7b9 ] |
| |
| When an I2C SMBus read operation fails, the MCP2221 internal state machine |
| may not reset correctly, causing subsequent transactions to fail. |
| |
| By adding a short delay and explicitly cancelling the last command, |
| we ensure the device is ready for the next operation. |
| |
| Fix an issue where i2cdetect was not able to detect all devices correctly |
| on the bus. |
| |
| Signed-off-by: Romain Sioen <romain.sioen@microchip.com> |
| Signed-off-by: Jiri Kosina <jkosina@suse.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/hid/hid-mcp2221.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c |
| index 589f13ff0b606..9fb98c8e1ffb7 100644 |
| --- a/drivers/hid/hid-mcp2221.c |
| +++ b/drivers/hid/hid-mcp2221.c |
| @@ -319,6 +319,8 @@ static int mcp_i2c_smbus_read(struct mcp2221 *mcp, |
| usleep_range(90, 100); |
| retries++; |
| } else { |
| + usleep_range(980, 1000); |
| + mcp_cancel_last_cmd(mcp); |
| return ret; |
| } |
| } else { |
| -- |
| 2.51.0 |
| |
