ahci: link FIS receive mode to memory allocation

There is no need to set/clear PxCMD.FRE on every port start/stop.

Also remove some already useless and now also incomplete port
reinitialization at startup.

diff --git a/drivers/ahci/ahci.c b/drivers/ahci/ahci.c
index 612501011b4b0f059d701507cfb37e27abb697c6..c04e41bedf7ace50a8ed1ab69c17475680a7a7ab 100644 (file)
--- a/drivers/ahci/ahci.c
+++ b/drivers/ahci/ahci.c
@@ -1202,10 +1202,6 @@ static void port_start(struct port_state *ps)
         */
        u32_t cmd;
 
-       /* Enable FIS receive. */
-       cmd = port_read(ps, AHCI_PORT_CMD);
-       port_write(ps, AHCI_PORT_CMD, cmd | AHCI_PORT_CMD_FRE);
-
        /* Reset status registers. */
        port_write(ps, AHCI_PORT_SERR, ~0);
        port_write(ps, AHCI_PORT_IS, ~0);
@@ -1294,15 +1290,6 @@ static void port_stop(struct port_state *ps)
                        PORTREG_DELAY);
 
                dprintf(V_INFO, ("%s: stopped\n", ahci_portname(ps)));
-
-               cmd = port_read(ps, AHCI_PORT_CMD);
-       }
-
-       if (cmd & (AHCI_PORT_CMD_FR | AHCI_PORT_CMD_FRE)) {
-               port_write(ps, AHCI_PORT_CMD, cmd & ~AHCI_PORT_CMD_FRE);
-
-               SPIN_UNTIL(!(port_read(ps, AHCI_PORT_CMD) & AHCI_PORT_CMD_FR),
-                       PORTREG_DELAY);
        }
 
        /* Reset status registers. */
@@ -1794,15 +1781,16 @@ static int port_exec(struct port_state *ps, int cmd, clock_t timeout)
  *===========================================================================*/
 static void port_alloc(struct port_state *ps)
 {
-       /* Allocate memory for the given port. We try to cram everything into
-        * one 4K-page in order to limit memory usage as much as possible.
-        * More memory may be allocated on demand later, but allocation failure
-        * should be fatal only here. Note that we do not allocate memory for
-        * sector padding here, because we do not know the device's sector size
-        * yet.
+       /* Allocate memory for the given port, and enable FIS receipt. We try
+        * to cram everything into one 4K-page in order to limit memory usage
+        * as much as possible. More memory may be allocated on demand later,
+        * but allocation failure should be fatal only here. Note that we do
+        * not allocate memory for sector padding here, because we do not know
+        * the device's sector size yet.
         */
        size_t fis_off, tmp_off, ct_off; int i;
        size_t ct_offs[NR_CMDS];
+       u32_t cmd;
 
        fis_off = AHCI_CL_SIZE + AHCI_FIS_SIZE - 1;
        fis_off -= fis_off % AHCI_FIS_SIZE;
@@ -1850,6 +1838,10 @@ static void port_alloc(struct port_state *ps)
        port_write(ps, AHCI_PORT_CLBU, 0);
        port_write(ps, AHCI_PORT_CLB, ps->cl_phys);
 
+       /* Enable FIS receive. */
+       cmd = port_read(ps, AHCI_PORT_CMD);
+       port_write(ps, AHCI_PORT_CMD, cmd | AHCI_PORT_CMD_FRE);
+
        ps->pad_base = NULL;
        ps->pad_size = 0;
 }
@@ -1859,10 +1851,22 @@ static void port_alloc(struct port_state *ps)
  *===========================================================================*/
 static void port_free(struct port_state *ps)
 {
-       /* Free previously allocated memory for the given port.
+       /* Disable FIS receipt for the given port, and free previously
+        * allocated memory.
         */
+       u32_t cmd;
        int i;
 
+       /* Disable FIS receive. */
+       cmd = port_read(ps, AHCI_PORT_CMD);
+
+       if (cmd & (AHCI_PORT_CMD_FR | AHCI_PORT_CMD_FRE)) {
+               port_write(ps, AHCI_PORT_CMD, cmd & ~AHCI_PORT_CMD_FRE);
+
+               SPIN_UNTIL(!(port_read(ps, AHCI_PORT_CMD) & AHCI_PORT_CMD_FR),
+                       PORTREG_DELAY);
+       }
+
        if (ps->pad_base != NULL)
                free_contig(ps->pad_base, ps->pad_size);
 
@@ -1897,9 +1901,6 @@ static void port_init(struct port_state *ps)
        ps->reg = (u32_t *) ((u8_t *) hba_state.base +
                AHCI_MEM_BASE_SIZE + AHCI_MEM_PORT_SIZE * (ps - port_state));
 
-       /* Make sure the port is in a known state. */
-       port_stop(ps);
-
        /* Allocate memory for the port. */
        port_alloc(ps);