From: Walter Murphy wmurphy@google.com
Note: These are timeout values and not delay values, so the event being timed out will complete whenever it is actually ready, with a measurement granularity of 1 millisecond, up till the timeout value. Therefore, there is no effect on SSD booting.
The values were determined by instrumenting the code and measuring the actual time taken by several different models of HDD for each of the parameters and then adding 50% more for the spinup value and just doubling the command timeout value.
Signed-off-by: Walter Murphy wmurphy@chromium.org Signed-off-by: Simon Glass sjg@chromium.org ---
drivers/block/ahci.c | 14 ++++++++++---- 1 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/block/ahci.c b/drivers/block/ahci.c index a05d9cf..719574f 100644 --- a/drivers/block/ahci.c +++ b/drivers/block/ahci.c @@ -52,6 +52,10 @@ hd_driveid_t *ataid[AHCI_MAX_PORTS]; #define MAX_SATA_BLOCKS_READ_WRITE 0x80 #endif
+/* Maximum timeouts for each event */ +#define WAIT_MS_DATAIO 5000 +#define WAIT_MS_LINKUP 4 + static inline u32 ahci_port_base(u32 base, u32 port) { return base + 0x100 + (port * 0x80); @@ -201,14 +205,14 @@ static int ahci_host_init(struct ahci_probe_ent *probe_ent) writel(PORT_CMD_SPIN_UP, port_mmio + PORT_CMD);
j = 0; - while (j < 1000) { + while (j < WAIT_MS_LINKUP) { tmp = readl(port_mmio + PORT_SCR_STAT); if ((tmp & 0xf) == 0x3) break; udelay(1000); j++; } - if (j == 1000) + if (j == WAIT_MS_LINKUP) debug("timeout.\n"); else debug("ok.\n"); @@ -429,7 +433,8 @@ static void ahci_set_feature(u8 port) writel(1, port_mmio + PORT_CMD_ISSUE); readl(port_mmio + PORT_CMD_ISSUE);
- if (waiting_for_cmd_completed(port_mmio + PORT_CMD_ISSUE, 150, 0x1)) { + if (waiting_for_cmd_completed(port_mmio + PORT_CMD_ISSUE, + WAIT_MS_DATAIO, 0x1)) { printf("set feature error on port %d!\n", port); } } @@ -535,7 +540,8 @@ static int ahci_device_data_io(u8 port, u8 *fis, int fis_len, u8 *buf,
writel_with_flush(1, port_mmio + PORT_CMD_ISSUE);
- if (waiting_for_cmd_completed(port_mmio + PORT_CMD_ISSUE, 150, 0x1)) { + if (waiting_for_cmd_completed(port_mmio + PORT_CMD_ISSUE, + WAIT_MS_DATAIO, 0x1)) { printf("timeout exit!\n"); return -1; }