Change Details

The ACPI Specification defines a Generic Address Structure (GAS), which is used to describe UART controller register layout in the SPCR table. The driver responsible for parsing it (uart_cpu_acpi) wrongly associates the Access Size field to the uart_bas's regshft and the register BitWidth to the regiowidth - according to the definitions it should be opposite. This problem remained hidded most likely because the majority of platforms use 32-bit registers (BitWidth) which are accessed with the according size (Dword). However on Marvell Armada 8k / Cn913x platforms, the 32-bit registers should be accessed with Byte granulity, which unveiled the issue. This patch fixes above by proper values assignment and slightly improved parsing.

The ACPI Specification defines a Generic Address Structure (GAS), which is used to describe UART controller register layout in the SPCR table. The driver responsible for parsing it (uart_cpu_acpi) wrongly associates the Access Size field to the uart_bas's regshft and the register BitWidth to the regiowidth - according to the definitions it should be opposite. This problem remained hidden most likely because the majority of platforms use 32-bit registers (BitWidth) which are accessed with the according size (Dword). However on Marvell Armada 8k / Cn913x platforms, the 32-bit registers should be accessed with Byte granulity, which unveiled the issue. This patch fixes above by proper values assignment and slightly improved parsing.

The ACPI Specification defines a Generic Address Structure (GAS), which is used to describe UART controller register layout in the SPCR table. The driver responsible for parsing it (uart_cpu_acpi) wrongly associates the Access Size field to the uart_bas's regshft and the register BitWidth to the regiowidth - according to the definitions it should be opposite. This problem remained hiddedn most likely because the majority of platforms use 32-bit registers (BitWidth) which are accessed with the according size (Dword). However on Marvell Armada 8k / Cn913x platforms, the 32-bit registers should be accessed with Byte granulity, which unveiled the issue. This patch fixes above by proper values assignment and slightly improved parsing.