[PATCH v2 0/2] fix sd power bug and modify phase-searching method

[PATCH v2 0/2] fix sd power bug and modify phase-searching method

[micky_ching]

From: Micky Ching <micky_ching@realsil.com.cn>

If the driver removed while sd/mmc card still in the slot, the card power
will not power down correctly, if we insert the driver module again,
UHS card will not switch to UHS mode. This bug is fixed in this patch.

We use another phase search method for tuning, which looks more
simple, and reduce some source code.

Micky Ching (2):
  mmc: rtsx: fix card poweroff bug
  mmc: rtsx: modify phase searching method for tunning

 drivers/mmc/host/rtsx_pci_sdmmc.c |  115 +++++++++++--------------------------
 include/linux/mfd/rtsx_pci.h      |    3 +-
 2 files changed, 36 insertions(+), 82 deletions(-)

--
1.7.9.5

[PATCH v2 1/2] mmc: rtsx: fix card poweroff bug

[micky_ching]

From: Micky Ching <micky_ching@realsil.com.cn>

If the host driver removed while card in the slot, the host will not
power off card power correctly. This bug is produced because host
eject flag set before the last mmc_set_ios callback, we should set the
eject flag after power off.

Signed-off-by: Micky Ching <micky_ching@realsil.com.cn>
---
 drivers/mmc/host/rtsx_pci_sdmmc.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c
index 375a880e..c9a7328 100644
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -1328,7 +1328,6 @@ static int rtsx_pci_sdmmc_drv_remove(struct platform_device *pdev)
 	pcr->slots[RTSX_SD_CARD].p_dev = NULL;
 	pcr->slots[RTSX_SD_CARD].card_event = NULL;
 	mmc = host->mmc;
-	host->eject = true;
 
 	mutex_lock(&host->host_mutex);
 	if (host->mrq) {
@@ -1346,6 +1345,8 @@ static int rtsx_pci_sdmmc_drv_remove(struct platform_device *pdev)
 	mutex_unlock(&host->host_mutex);
 
 	mmc_remove_host(mmc);
+	host->eject = true;
+
 	mmc_free_host(mmc);
 
 	dev_dbg(&(pdev->dev),
-- 
1.7.9.5

[PATCH v2 2/2] mmc: rtsx: modify phase searching method for tunning

[micky_ching]

From: Micky Ching <micky_ching@realsil.com.cn>

The new phase searching method is more concise and easier to
understand.

Signed-off-by: Micky Ching <micky_ching@realsil.com.cn>
---
 drivers/mmc/host/rtsx_pci_sdmmc.c |  112 +++++++++++--------------------------
 include/linux/mfd/rtsx_pci.h      |    3 +-
 2 files changed, 34 insertions(+), 81 deletions(-)

diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c
index c9a7328..0f4acb8 100644
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -31,16 +31,6 @@
 #include <linux/mfd/rtsx_pci.h>
 #include <asm/unaligned.h>
 
-/* SD Tuning Data Structure
- * Record continuous timing phase path
- */
-struct timing_phase_path {
-	int start;
-	int end;
-	int mid;
-	int len;
-};
-
 struct realtek_pci_sdmmc {
 	struct platform_device	*pdev;
 	struct rtsx_pcr		*pcr;
@@ -511,85 +501,47 @@ static int sd_change_phase(struct realtek_pci_sdmmc *host,
 	return 0;
 }
 
-static u8 sd_search_final_phase(struct realtek_pci_sdmmc *host, u32 phase_map)
+static inline u32 test_phase_bit(u32 phase_map, unsigned int bit)
 {
-	struct timing_phase_path path[MAX_PHASE + 1];
-	int i, j, cont_path_cnt;
-	int new_block, max_len, final_path_idx;
-	u8 final_phase = 0xFF;
+	bit &= RTSX_PHASE_MASK;
+	return phase_map & (1 << bit);
+}
 
-	/* Parse phase_map, take it as a bit-ring */
-	cont_path_cnt = 0;
-	new_block = 1;
-	j = 0;
-	for (i = 0; i < MAX_PHASE + 1; i++) {
-		if (phase_map & (1 << i)) {
-			if (new_block) {
-				new_block = 0;
-				j = cont_path_cnt++;
-				path[j].start = i;
-				path[j].end = i;
-			} else {
-				path[j].end = i;
-			}
-		} else {
-			new_block = 1;
-			if (cont_path_cnt) {
-				/* Calculate path length and middle point */
-				int idx = cont_path_cnt - 1;
-				path[idx].len =
-					path[idx].end - path[idx].start + 1;
-				path[idx].mid =
-					path[idx].start + path[idx].len / 2;
-			}
-		}
-	}
+static int sd_get_phase_len(u32 phase_map, unsigned int start_bit)
+{
+	int i;
 
-	if (cont_path_cnt == 0) {
-		dev_dbg(sdmmc_dev(host), "No continuous phase path\n");
-		goto finish;
-	} else {
-		/* Calculate last continuous path length and middle point */
-		int idx = cont_path_cnt - 1;
-		path[idx].len = path[idx].end - path[idx].start + 1;
-		path[idx].mid = path[idx].start + path[idx].len / 2;
+	for (i = 0; i < RTSX_PHASE_MAX; i++) {
+		if (test_phase_bit(phase_map, start_bit + i) == 0)
+			return i;
 	}
+	return RTSX_PHASE_MAX;
+}
+
+static u8 sd_search_final_phase(struct realtek_pci_sdmmc *host, u32 phase_map)
+{
+	int start = 0, len = 0;
+	int start_final = 0, len_final = 0;
+	u8 final_phase = 0xFF;
 
-	/* Connect the first and last continuous paths if they are adjacent */
-	if (!path[0].start && (path[cont_path_cnt - 1].end == MAX_PHASE)) {
-		/* Using negative index */
-		path[0].start = path[cont_path_cnt - 1].start - MAX_PHASE - 1;
-		path[0].len += path[cont_path_cnt - 1].len;
-		path[0].mid = path[0].start + path[0].len / 2;
-		/* Convert negative middle point index to positive one */
-		if (path[0].mid < 0)
-			path[0].mid += MAX_PHASE + 1;
-		cont_path_cnt--;
+	if (phase_map == 0) {
+		dev_err(sdmmc_dev(host), "phase error: [map:%x]\n", phase_map);
+		return final_phase;
 	}
 
-	/* Choose the longest continuous phase path */
-	max_len = 0;
-	final_phase = 0;
-	final_path_idx = 0;
-	for (i = 0; i < cont_path_cnt; i++) {
-		if (path[i].len > max_len) {
-			max_len = path[i].len;
-			final_phase = (u8)path[i].mid;
-			final_path_idx = i;
+	while (start < RTSX_PHASE_MAX) {
+		len = sd_get_phase_len(phase_map, start);
+		if (len_final < len) {
+			start_final = start;
+			len_final = len;
 		}
-
-		dev_dbg(sdmmc_dev(host), "path[%d].start = %d\n",
-				i, path[i].start);
-		dev_dbg(sdmmc_dev(host), "path[%d].end = %d\n",
-				i, path[i].end);
-		dev_dbg(sdmmc_dev(host), "path[%d].len = %d\n",
-				i, path[i].len);
-		dev_dbg(sdmmc_dev(host), "path[%d].mid = %d\n",
-				i, path[i].mid);
+		start += len ? len : 1;
 	}
 
-finish:
-	dev_dbg(sdmmc_dev(host), "Final chosen phase: %d\n", final_phase);
+	final_phase = (start_final + len_final / 2) & RTSX_PHASE_MASK;
+	dev_dbg(sdmmc_dev(host), "phase: [map:%x] [maxlen:%d] [final:%d]\n",
+		phase_map, len_final, final_phase);
+
 	return final_phase;
 }
 
@@ -635,7 +587,7 @@ static int sd_tuning_phase(struct realtek_pci_sdmmc *host,
 	int err, i;
 	u32 raw_phase_map = 0;
 
-	for (i = MAX_PHASE; i >= 0; i--) {
+	for (i = 0; i < RTSX_PHASE_MAX; i++) {
 		err = sd_tuning_rx_cmd(host, opcode, (u8)i);
 		if (err == 0)
 			raw_phase_map |= 1 << i;
diff --git a/include/linux/mfd/rtsx_pci.h b/include/linux/mfd/rtsx_pci.h
index 0ce7721..bdc79c5 100644
--- a/include/linux/mfd/rtsx_pci.h
+++ b/include/linux/mfd/rtsx_pci.h
@@ -144,7 +144,8 @@
 #define HOST_TO_DEVICE		0
 #define DEVICE_TO_HOST		1
 
-#define MAX_PHASE		31
+#define RTSX_PHASE_MAX		32
+#define RTSX_PHASE_MASK		(RTSX_PHASE_MAX - 1)
 #define RX_TUNING_CNT		3
 
 /* SG descriptor */
-- 
1.7.9.5