Method write_config_register

pci/src/configuration.rs:907–966

(
        &mut self,
        reg_idx: usize,
        offset: u64,
        data: &[u8],
    )

    }

    pub fn write_config_register(
        &mut self,
        reg_idx: usize,
        offset: u64,
        data: &[u8],
    ) -> Vec<BarReprogrammingParams> {
        if offset as usize + data.len() > 4 {
            return Vec::new();
        }

        // Handle potential write to MSI-X message control register
        if let Some(msix_cap_reg_idx) = self.msix_cap_reg_idx
            && let Some(msix_config) = &self.msix_config
        {
            if msix_cap_reg_idx == reg_idx && offset == 2 && data.len() == 2 {
                msix_config
                    .lock()
                    .unwrap()
                    .set_msg_ctl(LittleEndian::read_u16(data));
            } else if msix_cap_reg_idx == reg_idx && offset == 0 && data.len() == 4 {
                msix_config
                    .lock()
                    .unwrap()
                    .set_msg_ctl((LittleEndian::read_u32(data) >> 16) as u16);
            }
        }

        match data.len() {
            1 => self.write_byte(reg_idx * 4 + offset as usize, data[0]),
            2 => self.write_word(
                reg_idx * 4 + offset as usize,
                u16::from(data[0]) | (u16::from(data[1]) << 8),
            ),
            4 => self.write_reg(reg_idx, LittleEndian::read_u32(data)),
            _ => (),
        }

        if let Some(param) = self.detect_bar_reprogramming(reg_idx, data) {
            self.pending_bar_reprogram.push(param);
        }

        if !self.pending_bar_reprogram.is_empty() {
            // Return bar reprogramming only if the MSE bit is enabled;
            if self.read_config_register(COMMAND_REG) & COMMAND_REG_MEMORY_SPACE_MASK
                == COMMAND_REG_MEMORY_SPACE_MASK
            {
                info!(
                    "BAR reprogramming parameter is returned: {:x?}",
                    self.pending_bar_reprogram
                );
                return self.pending_bar_reprogram.drain(..).collect();
            }
            info!(
                "MSE bit is disabled. No BAR reprogramming parameter is returned: {:x?}",
                self.pending_bar_reprogram
            );
        }