Add retry tuning up to 10 times if we fail to find
a failing region or no passing itapdly. This is
necessary since some eMMC has been observed to never
find a failing itapdly on the first couple of tuning
iterations, but eventually does. Keep count of current
tuning iteration using tuning_loop. It has been observed
that the tuning algorithm does not need to loop more
than 10 times before finding a failing itapdly.
Signed-off-by: Judith Mendez <jm@xxxxxx>
---
Changes since v2:
- Use do while loop instead of while in patch 1/2
- Move initialization of tuning_loop to sdhci_am654_init
- Separate error path in patch 1/2
---
drivers/mmc/host/sdhci_am654.c | 46 ++++++++++++++++++++++++++--------
1 file changed, 35 insertions(+), 11 deletions(-)
diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
index 64e10f7c9faa3..13da003363e1d 100644
--- a/drivers/mmc/host/sdhci_am654.c
+++ b/drivers/mmc/host/sdhci_am654.c
@@ -86,6 +86,7 @@
#define CLOCK_TOO_SLOW_HZ 50000000
#define SDHCI_AM654_AUTOSUSPEND_DELAY -1
+#define RETRY_TUNING_MAX 10
/* Command Queue Host Controller Interface Base address */
#define SDHCI_AM654_CQE_BASE_ADDR 0x200
@@ -151,6 +152,7 @@ struct sdhci_am654_data {
u32 flags;
u32 quirks;
bool dll_enable;
+ u32 tuning_loop;
#define SDHCI_AM654_QUIRK_FORCE_CDTEST BIT(0)
};
@@ -443,7 +445,7 @@ static u32 sdhci_am654_cqhci_irq(struct sdhci_host *host, u32 intmask)
#define ITAPDLY_LENGTH 32
#define ITAPDLY_LAST_INDEX (ITAPDLY_LENGTH - 1)
-static u32 sdhci_am654_calculate_itap(struct sdhci_host *host, struct window
+static int sdhci_am654_calculate_itap(struct sdhci_host *host, struct window
*fail_window, u8 num_fails, bool circular_buffer)
{
u8 itap = 0, start_fail = 0, end_fail = 0, pass_length = 0;
@@ -453,12 +455,14 @@ static u32 sdhci_am654_calculate_itap(struct sdhci_host *host, struct window
int prev_fail_end = -1;
u8 i;
- if (!num_fails)
- return ITAPDLY_LAST_INDEX >> 1;
+ if (!num_fails) {
+ /* Retry tuning */
+ return -1;
+ }
if (fail_window->length == ITAPDLY_LENGTH) {
- dev_err(dev, "No passing ITAPDLY, return 0\n");
- return 0;
+ /* Retry tuning */
+ return -1;
}
first_fail_start = fail_window->start;
@@ -494,8 +498,8 @@ static u32 sdhci_am654_calculate_itap(struct sdhci_host *host, struct window
return (itap > ITAPDLY_LAST_INDEX) ? ITAPDLY_LAST_INDEX >> 1 : itap;
}
-static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
- u32 opcode)
+static int sdhci_am654_do_tuning(struct sdhci_host *host,
+ u32 opcode)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
@@ -532,13 +536,30 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
if (fail_window[fail_index].length != 0)
fail_index++;
- itap = sdhci_am654_calculate_itap(host, fail_window, fail_index,
- sdhci_am654->dll_enable);
+ return sdhci_am654_calculate_itap(host, fail_window, fail_index,
+ sdhci_am654->dll_enable);
+}
- sdhci_am654_write_itapdly(sdhci_am654, itap, sdhci_am654->itap_del_ena[timing]);
+static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
+ u32 opcode)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+ unsigned char timing = host->mmc->ios.timing;
+ int itapdly;
+ do {
+ itapdly = sdhci_am654_do_tuning(host, opcode);
+ if (itapdly >= 0)
+ break;
+ } while (++sdhci_am654->tuning_loop < RETRY_TUNING_MAX);
+
+ if (itapdly < 0)
+ return -1;
+
+ sdhci_am654_write_itapdly(sdhci_am654, itapdly, sdhci_am654->itap_del_ena[timing]);
/* Save ITAPDLY */
- sdhci_am654->itap_del_sel[timing] = itap;
+ sdhci_am654->itap_del_sel[timing] = itapdly;
return 0;
}
@@ -742,6 +763,9 @@ static int sdhci_am654_init(struct sdhci_host *host)
regmap_update_bits(sdhci_am654->base, CTL_CFG_3, TUNINGFORSDR50_MASK,
TUNINGFORSDR50_MASK);
+ /* Use to re-execute tuning */
+ sdhci_am654->tuning_loop = 0;
+
ret = sdhci_setup_host(host);
if (ret)
return ret;
--
2.46.0
