ubuntu fica sem som no macbook

[robertonazarethguedes]

fiz dualbot mac e ubuntu e o ubuntu fica sem som. já fiz o que mandava num topico aqui mas não deu.

robertonazareth1@MacBook:~$ lspci
00:00.0 Host bridge: nVidia Corporation MCP89 HOST Bridge (rev a1)
00:00.1 RAM memory: nVidia Corporation MCP89 Memory Controller (rev a1)
00:01.0 RAM memory: nVidia Corporation Device 0d6d (rev a1)
00:01.1 RAM memory: nVidia Corporation Device 0d6e (rev a1)
00:01.2 RAM memory: nVidia Corporation Device 0d6f (rev a1)
00:01.3 RAM memory: nVidia Corporation Device 0d70 (rev a1)
00:02.0 RAM memory: nVidia Corporation Device 0d71 (rev a1)
00:02.1 RAM memory: nVidia Corporation Device 0d72 (rev a1)
00:03.0 ISA bridge: nVidia Corporation MCP89 LPC Bridge (rev a2)
00:03.1 RAM memory: nVidia Corporation MCP89 Memory Controller (rev a1)
00:03.2 SMBus: nVidia Corporation MCP89 SMBus (rev a1)
00:03.3 RAM memory: nVidia Corporation MCP89 Memory Controller (rev a1)
00:03.4 Co-processor: nVidia Corporation MCP89 Co-Processor (rev a1)
00:04.0 USB Controller: nVidia Corporation MCP89 OHCI USB 1.1 Controller (rev a1)
00:04.1 USB Controller: nVidia Corporation MCP89 EHCI USB 2.0 Controller (rev a2)
00:06.0 USB Controller: nVidia Corporation MCP89 OHCI USB 1.1 Controller (rev a1)
00:06.1 USB Controller: nVidia Corporation MCP89 EHCI USB 2.0 Controller (rev a2)
00:08.0 Audio device: nVidia Corporation MCP89 High Definition Audio (rev a2)
00:09.0 Ethernet controller: nVidia Corporation MCP89 Ethernet (rev a1)
00:0a.0 IDE interface: nVidia Corporation MCP89 SATA Controller (rev a2)
00:0b.0 RAM memory: nVidia Corporation Device 0d75 (rev a1)
00:15.0 PCI bridge: nVidia Corporation Device 0d9b (rev a1)
00:17.0 PCI bridge: nVidia Corporation MCP89 PCI Express Bridge (rev a1)
01:00.0 Network controller: Broadcom Corporation BCM43224 802.11a/b/g/n (rev 01)
02:00.0 VGA compatible controller: nVidia Corporation Device 08a0 (rev a2)