The theory is that the so called workaround in pwr_reg_rdwr() is the actual reader of the data in 32-bit chunks. For some reason the 8-bit IO won't fail after that. Replace the workaround by using 32-bit IO explicitly and then memcpy() as much data as was requested by the user. The same approach is already in use in intel_scu_ipc_dev_command_with_size(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- drivers/platform/x86/intel_scu_ipc.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c index 5b16d29c93d7..290b38627542 100644 --- a/drivers/platform/x86/intel_scu_ipc.c +++ b/drivers/platform/x86/intel_scu_ipc.c @@ -217,12 +217,6 @@ static inline u8 ipc_read_status(struct intel_scu_ipc_dev *scu) return __raw_readl(scu->ipc_base + IPC_STATUS); } -/* Read ipc byte data */ -static inline u8 ipc_data_readb(struct intel_scu_ipc_dev *scu, u32 offset) -{ - return readb(scu->ipc_base + IPC_READ_BUFFER + offset); -} - /* Read ipc u32 data */ static inline u32 ipc_data_readl(struct intel_scu_ipc_dev *scu, u32 offset) { @@ -325,11 +319,10 @@ static int pwr_reg_rdwr(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data, } err = intel_scu_ipc_check_status(scu); - if (!err && id == IPC_CMD_PCNTRL_R) { /* Read rbuf */ - /* Workaround: values are read as 0 without memcpy_fromio */ - memcpy_fromio(cbuf, scu->ipc_base + 0x90, 16); - for (nc = 0; nc < count; nc++) - data[nc] = ipc_data_readb(scu, nc); + if (!err) { /* Read rbuf */ + for (nc = 0, offset = 0; nc < 4; nc++, offset += 4) + wbuf[nc] = ipc_data_readl(scu, offset); + memcpy(data, wbuf, count); } mutex_unlock(&ipclock); return err; -- 2.43.0.rc1.1336.g36b5255a03ac