diff --git a/drivers/gpu/drm/xe/regs/xe_reg_defs.h b/drivers/gpu/drm/xe/regs/xe_reg_defs.h index 6e20fc2de9ff..c50e7650c09a 100644 --- a/drivers/gpu/drm/xe/regs/xe_reg_defs.h +++ b/drivers/gpu/drm/xe/regs/xe_reg_defs.h @@ -60,7 +60,16 @@ struct xe_reg_mcr { /** * XE_REG_OPTION_MASKED - Register is "masked", with upper 16 bits marking the - * read/written bits on the lower 16 bits. + * written bits on the lower 16 bits. + * + * It only applies to registers explicitly marked in bspec with + * "Access: Masked". Registers with this option can have write operations to + * specific lower bits by setting the corresponding upper bits. Other bits will + * not be affected. This allows register writes without needing a RMW cycle and + * without caching in software the register value. + * + * Example: a write with value 0x00010001 will set bit 0 and all other bits + * retain their previous values. * * To be used with XE_REG(). XE_REG_MCR() and XE_REG_INITIALIZER() */