From: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> [ Upstream commit b3db266fb031fba88c423d4bb8983a73a3db6527 ] Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was increased from 16 to 256. In order to avoid overflowing reads for older systems, add a mechanism to use the read UCSI version to truncate read sizes on UCSI v1.2. Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> Reviewed-by: Prashant Malani <pmalani@xxxxxxxxxxxx> Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240209143723.v5.1.Iacf5570a66b82b73ef03daa6557e2fc0db10266a@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/usb/typec/ucsi/ucsi.c | 26 ++++++++++++++++++++++++-- drivers/usb/typec/ucsi/ucsi.h | 11 +++++++++++ 2 files changed, 35 insertions(+), 2 deletions(-) diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 14f5a7bfae2e9..7c5cecdd93d66 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -36,6 +36,19 @@ */ #define UCSI_SWAP_TIMEOUT_MS 5000 +static int ucsi_read_message_in(struct ucsi *ucsi, void *buf, + size_t buf_size) +{ + /* + * Below UCSI 2.0, MESSAGE_IN was limited to 16 bytes. Truncate the + * reads here. + */ + if (ucsi->version <= UCSI_VERSION_1_2) + buf_size = clamp(buf_size, 0, 16); + + return ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, buf, buf_size); +} + static int ucsi_acknowledge_command(struct ucsi *ucsi) { u64 ctrl; @@ -72,7 +85,7 @@ static int ucsi_read_error(struct ucsi *ucsi) if (ret < 0) return ret; - ret = ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, &error, sizeof(error)); + ret = ucsi_read_message_in(ucsi, &error, sizeof(error)); if (ret) return ret; @@ -170,7 +183,7 @@ int ucsi_send_command(struct ucsi *ucsi, u64 command, length = ret; if (data) { - ret = ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, data, size); + ret = ucsi_read_message_in(ucsi, data, size); if (ret) goto out; } @@ -1558,6 +1571,15 @@ int ucsi_register(struct ucsi *ucsi) if (!ucsi->version) return -ENODEV; + /* + * Version format is JJ.M.N (JJ = Major version, M = Minor version, + * N = sub-minor version). + */ + dev_dbg(ucsi->dev, "Registered UCSI interface with version %x.%x.%x", + UCSI_BCD_GET_MAJOR(ucsi->version), + UCSI_BCD_GET_MINOR(ucsi->version), + UCSI_BCD_GET_SUBMINOR(ucsi->version)); + queue_delayed_work(system_long_wq, &ucsi->work, 0); ucsi_debugfs_register(ucsi); diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h index 6478016d5cb8b..bec920fa6b8ae 100644 --- a/drivers/usb/typec/ucsi/ucsi.h +++ b/drivers/usb/typec/ucsi/ucsi.h @@ -23,6 +23,17 @@ struct dentry; #define UCSI_CONTROL 8 #define UCSI_MESSAGE_IN 16 #define UCSI_MESSAGE_OUT 32 +#define UCSIv2_MESSAGE_OUT 272 + +/* UCSI versions */ +#define UCSI_VERSION_1_2 0x0120 +#define UCSI_VERSION_2_0 0x0200 +#define UCSI_VERSION_2_1 0x0210 +#define UCSI_VERSION_3_0 0x0300 + +#define UCSI_BCD_GET_MAJOR(_v_) (((_v_) >> 8) & 0xFF) +#define UCSI_BCD_GET_MINOR(_v_) (((_v_) >> 4) & 0x0F) +#define UCSI_BCD_GET_SUBMINOR(_v_) ((_v_) & 0x0F) /* Command Status and Connector Change Indication (CCI) bits */ #define UCSI_CCI_CONNECTOR(_c_) (((_c_) & GENMASK(7, 1)) >> 1) -- 2.43.0
