Added boot environment option 'ata_no_dma' to disable DMA.

diff --git a/drivers/at_wini/at_wini.c b/drivers/at_wini/at_wini.c
index 4273ce55a777f8c7c4a0548c02627014f2d0ea2d..8599f2686d83181a10d1a6d386f9be05f9e9381a 100644 (file)
--- a/drivers/at_wini/at_wini.c
+++ b/drivers/at_wini/at_wini.c
@@ -252,7 +252,7 @@ struct command {
 int timeout_ticks = DEF_TIMEOUT_TICKS, max_errors = MAX_ERRORS;
 int wakeup_ticks = WAKEUP;
 long w_standard_timeouts = 0, w_pci_debug = 0, w_instance = 0,
-       atapi_debug = 0;
+       disable_dma = 0, atapi_debug = 0;
 
 int w_testing = 0, w_silent = 0;
 
@@ -419,20 +419,19 @@ PRIVATE void init_params()
   env_parse("ata_std_timeout", "d", 0, &w_standard_timeouts, 0, 1);
   env_parse("ata_pci_debug", "d", 0, &w_pci_debug, 0, 1);
   env_parse("ata_instance", "d", 0, &w_instance, 0, 8);
+  env_parse("ata_no_dma", "d", 0, &disable_dma, 0, 1);
   env_parse("atapi_debug", "d", 0, &atapi_debug, 0, 1);
 
+  if (disable_dma)
+       printf("DMA for ATA devices is disabled.\n");
+
   s= sys_umap(SELF, D, (vir_bytes)dma_buf, sizeof(dma_buf), &dma_buf_phys);
   if (s != 0)
        panic("at_wini", "can't map dma buffer", s);
-  printf("init_params: got phys 0x%x for dma buffer at 0x%x\n",
-       dma_buf_phys, (vir_bytes)dma_buf);
 
   s= sys_umap(SELF, D, (vir_bytes)prdt, sizeof(prdt), &prdt_phys);
   if (s != 0)
        panic("at_wini", "can't map prd table", s);
-  printf("init_params: got phys 0x%x for prd table at 0x%x\n",
-       prdt_phys, (vir_bytes)prdt);
-
 
   if (w_instance == 0) {
          /* Get the number of drives from the BIOS data area */
@@ -824,7 +823,9 @@ PRIVATE int w_identify()
                                        NO_NUM);
                        }
                }
-               if (id_dma && dma_base)
+               if (disable_dma)
+                       ;       /* DMA is disabled */
+               else if (id_dma && dma_base)
                {
                        w= id_word(ID_MULTIWORD_DMA);
                        if (w & (ID_MWDMA_2_SUP|ID_MWDMA_1_SUP|ID_MWDMA_0_SUP))