You must wait for inb(0x64) & 1 before reading from 0x60.
The code clearly shows that all the ISR does is read from the status port, and if there is data available, read it from the data port. It only does nothing in the unlikely case that no data is available (could be a spurious interrupt.) I have written code like this before. There is no waiting, no polling. Receive an interrupt, read a byte. Some devices will actually let you read multiple bytes (just keep reading until one of the bits in the status register goes off.)
You're claiming it would significantly increase cost to enhance an existing interface (as opposed to redesigning everything and the nontrivial NRE of that?), on a laptop that itself costs far more than the majority of others using a standard or slightly enhanced standard interface.
The code clearly shows that all the ISR does is read from the status port, and if there is data available, read it from the data port. It only does nothing in the unlikely case that no data is available (could be a spurious interrupt.) I have written code like this before. There is no waiting, no polling. Receive an interrupt, read a byte. Some devices will actually let you read multiple bytes (just keep reading until one of the bits in the status register goes off.)
You're claiming it would significantly increase cost to enhance an existing interface (as opposed to redesigning everything and the nontrivial NRE of that?), on a laptop that itself costs far more than the majority of others using a standard or slightly enhanced standard interface.