diff options
Diffstat (limited to 'drivers/firmware/google/gsmi.c')
| -rw-r--r-- | drivers/firmware/google/gsmi.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/firmware/google/gsmi.c b/drivers/firmware/google/gsmi.c index edaa4e5d84ad..5b2011ebbe26 100644 --- a/drivers/firmware/google/gsmi.c +++ b/drivers/firmware/google/gsmi.c @@ -76,6 +76,7 @@ #define GSMI_CMD_LOG_S0IX_RESUME 0x0b #define GSMI_CMD_CLEAR_CONFIG 0x20 #define GSMI_CMD_HANDSHAKE_TYPE 0xC1 +#define GSMI_CMD_RESERVED 0xff /* Magic entry type for kernel events */ #define GSMI_LOG_ENTRY_TYPE_KERNEL 0xDEAD @@ -746,6 +747,7 @@ MODULE_DEVICE_TABLE(dmi, gsmi_dmi_table); static __init int gsmi_system_valid(void) { u32 hash; + u16 cmd, result; if (!dmi_check_system(gsmi_dmi_table)) return -ENODEV; @@ -780,6 +782,23 @@ static __init int gsmi_system_valid(void) return -ENODEV; } + /* Test the smihandler with a bogus command. If it leaves the + * calling argument in %ax untouched, there is no handler for + * GSMI commands. + */ + cmd = GSMI_CALLBACK | GSMI_CMD_RESERVED << 8; + asm volatile ( + "outb %%al, %%dx\n\t" + : "=a" (result) + : "0" (cmd), + "d" (acpi_gbl_FADT.smi_command) + : "memory", "cc" + ); + if (cmd == result) { + pr_info("gsmi: no gsmi handler in firmware\n"); + return -ENODEV; + } + /* Found */ return 0; } @@ -1016,6 +1035,9 @@ out_err: dma_pool_destroy(gsmi_dev.dma_pool); platform_device_unregister(gsmi_dev.pdev); pr_info("gsmi: failed to load: %d\n", ret); +#ifdef CONFIG_PM + platform_driver_unregister(&gsmi_driver_info); +#endif return ret; } @@ -1037,6 +1059,9 @@ static void __exit gsmi_exit(void) gsmi_buf_free(gsmi_dev.name_buf); dma_pool_destroy(gsmi_dev.dma_pool); platform_device_unregister(gsmi_dev.pdev); +#ifdef CONFIG_PM + platform_driver_unregister(&gsmi_driver_info); +#endif } module_init(gsmi_init); |