Merge "ARM: dts: msm: enable SDR104 workaround for MSM8998"

Documentation/devicetree/bindings/mmc/sdhci-msm.txt

@@ -75,6 +75,11 @@ Optional Properties:
 						during clock scaling. If this property is not
 						defined, then it falls back to the default HS
 						bus speed mode to maintain backward compatibility.
+	- qcom,sdr104-wa: On Certain chipsets, SDR104 mode might be unstable causing CRC errors
+			  on the interface. So there is a workaround implemented to skip printing
+			  register dumps on CRC errors and also downgrade bus speed mode to
+			  SDR50/DDR50 in case of continuous CRC errors. Set this flag to enable
+			  this workaround.
 
 In the following, <supply> can be vdd (flash core voltage) or vdd-io (I/O voltage).
 	- qcom,<supply>-always-on - specifies whether supply should be kept "on" always.

arch/arm/boot/dts/qcom/msm8998.dtsi

@@ -1575,6 +1575,8 @@
 		qcom,bus-bw-vectors-bps = <0 400000 20000000 25000000 50000000
 						100000000 200000000 4294967295>;
 
+		qcom,sdr104-wa;
+
 		status = "disabled";
 	};
 

drivers/mmc/card/block.c

@@ -2189,6 +2189,17 @@ static int mmc_blk_err_check(struct mmc_card *card,
 	int need_retune = card->host->need_retune;
 	int ecc_err = 0, gen_err = 0;
 
+	if (card->host->sdr104_wa && mmc_card_sd(card) &&
+	    (card->host->ios.timing == MMC_TIMING_UHS_SDR104) &&
+	    !card->sdr104_blocked &&
+	    (brq->data.error == -EILSEQ ||
+	     brq->data.error == -EIO ||
+	     brq->data.error == -ETIMEDOUT ||
+	     brq->cmd.error == -EILSEQ ||
+	     brq->cmd.error == -EIO ||
+	     brq->cmd.error == -ETIMEDOUT))
+		card->err_in_sdr104 = true;
+
 	/*
 	 * sbc.error indicates a problem with the set block count
 	 * command.  No data will have been transferred.
@@ -3645,6 +3656,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 	struct mmc_async_req *areq;
 	const u8 packed_nr = 2;
 	u8 reqs = 0;
+	bool reset = false;
 #ifdef CONFIG_MMC_SIMULATE_MAX_SPEED
 	unsigned long waitfor = jiffies;
 #endif
@@ -3690,6 +3702,26 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 		type = rq_data_dir(req) == READ ? MMC_BLK_READ : MMC_BLK_WRITE;
 		mmc_queue_bounce_post(mq_rq);
 
+		if (card->err_in_sdr104) {
+			/*
+			 * Data CRC/timeout errors will manifest as CMD/DATA
+			 * ERR. But we'd like to retry these too.
+			 * Moreover, no harm done if this fails too for multiple
+			 * times, we anyway reduce the bus-speed and retry the
+			 * same request.
+			 * If that fails too, we don't override this status.
+			 */
+			if (status == MMC_BLK_ABORT ||
+			    status == MMC_BLK_CMD_ERR ||
+			    status == MMC_BLK_DATA_ERR ||
+			    status == MMC_BLK_RETRY)
+				/* reset on all of these errors and retry */
+				reset = true;
+
+			status = MMC_BLK_RETRY;
+			card->err_in_sdr104 = false;
+		}
+
 		switch (status) {
 		case MMC_BLK_SUCCESS:
 		case MMC_BLK_PARTIAL:
@@ -3730,8 +3762,32 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 			break;
 		case MMC_BLK_RETRY:
 			retune_retry_done = brq->retune_retry_done;
-			if (retry++ < MMC_BLK_MAX_RETRIES)
+			if (retry++ < MMC_BLK_MAX_RETRIES) {
 				break;
+			} else if (reset) {
+				reset = false;
+				/*
+				 * If we exhaust all the retries due to
+				 * CRC/timeout errors in SDR140 mode with UHS SD
+				 * cards, re-configure the card in SDR50
+				 * bus-speed mode.
+				 * All subsequent re-init of this card will be
+				 * in SDR50 mode, unless it is removed and
+				 * re-inserted. When new UHS SD cards are
+				 * inserted, it may start at SDR104 mode if
+				 * supported by the card.
+				 */
+				pr_err("%s: blocked SDR104, lower the bus-speed (SDR50 / DDR50)\n",
+					req->rq_disk->disk_name);
+				mmc_host_clear_sdr104(card->host);
+				mmc_suspend_clk_scaling(card->host);
+				mmc_blk_reset(md, card->host, type);
+				/* SDR104 mode is blocked from now on */
+				card->sdr104_blocked = true;
+				/* retry 5 times again */
+				retry = 0;
+				break;
+			}
 			/* Fall through */
 		case MMC_BLK_ABORT:
 			if (!mmc_blk_reset(md, card->host, type) &&

drivers/mmc/core/core.c

@@ -4040,6 +4040,10 @@ int _mmc_detect_card_removed(struct mmc_host *host)
 
 	if (ret) {
 		mmc_card_set_removed(host->card);
+		if (host->card->sdr104_blocked) {
+			mmc_host_set_sdr104(host);
+			host->card->sdr104_blocked = false;
+		}
 		pr_debug("%s: card remove detected\n", mmc_hostname(host));
 	}
 

drivers/mmc/core/core.h

@@ -80,7 +80,6 @@ void mmc_init_context_info(struct mmc_host *host);
 
 extern bool mmc_can_scale_clk(struct mmc_host *host);
 extern int mmc_init_clk_scaling(struct mmc_host *host);
-extern int mmc_suspend_clk_scaling(struct mmc_host *host);
 extern int mmc_resume_clk_scaling(struct mmc_host *host);
 extern int mmc_exit_clk_scaling(struct mmc_host *host);
 extern unsigned long mmc_get_max_frequency(struct mmc_host *host);

drivers/mmc/core/sd.c

@@ -1285,6 +1285,8 @@ static int _mmc_sd_resume(struct mmc_host *host)
 #endif
 	mmc_card_clr_suspended(host->card);
 
+	if (host->card->sdr104_blocked)
+		goto out;
 	err = mmc_resume_clk_scaling(host);
 	if (err) {
 		pr_err("%s: %s: fail to resume clock scaling (%d)\n",

drivers/mmc/host/sdhci-msm.c

@@ -1960,6 +1960,8 @@ struct sdhci_msm_pltfm_data *sdhci_msm_populate_pdata(struct device *dev,
 	if (of_get_property(np, "qcom,core_3_0v_support", NULL))
 		pdata->core_3_0v_support = true;
 
+	pdata->sdr104_wa = of_property_read_bool(np, "qcom,sdr104-wa");
+
 	return pdata;
 out:
 	return NULL;
@@ -4579,6 +4581,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	if (msm_host->pdata->nonhotplug)
 		msm_host->mmc->caps2 |= MMC_CAP2_NONHOTPLUG;
 
+	msm_host->mmc->sdr104_wa = msm_host->pdata->sdr104_wa;
 
 	/* Initialize ICE if present */
 	if (msm_host->ice.pdev) {

drivers/mmc/host/sdhci-msm.h

@@ -153,6 +153,7 @@ struct sdhci_msm_pltfm_data {
 	u32 ice_clk_min;
 	struct sdhci_msm_pm_qos_data pm_qos_data;
 	bool core_3_0v_support;
+	bool sdr104_wa;
 };
 
 struct sdhci_msm_bus_vote {

drivers/mmc/host/sdhci.c

@@ -3083,7 +3083,10 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 			       mmc_hostname(host->mmc), intmask,
 			       host->data->error, ktime_to_ms(ktime_sub(
 			       ktime_get(), host->data_start_time)));
-			sdhci_dumpregs(host);
+
+			if (!host->mmc->sdr104_wa ||
+			    (host->mmc->ios.timing != MMC_TIMING_UHS_SDR104))
+				sdhci_dumpregs(host);
 		}
 		sdhci_finish_data(host);
 	} else {

include/linux/mmc/card.h

@@ -434,6 +434,8 @@ struct mmc_card {
 	enum mmc_pon_type pon_type;
 	bool cmdq_init;
 	struct mmc_bkops_info bkops;
+	bool err_in_sdr104;
+	bool sdr104_blocked;
 };
 
 /*

include/linux/mmc/core.h

@@ -169,6 +169,7 @@ extern int __mmc_switch_cmdq_mode(struct mmc_command *cmd, u8 set, u8 index,
 extern int mmc_send_tuning(struct mmc_host *host, u32 opcode, int *cmd_error);
 extern int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd);
 extern int mmc_set_auto_bkops(struct mmc_card *card, bool enable);
+extern int mmc_suspend_clk_scaling(struct mmc_host *host);
 
 #define MMC_ERASE_ARG		0x00000000
 #define MMC_SECURE_ERASE_ARG	0x80000000

include/linux/mmc/host.h

@@ -595,6 +595,7 @@ struct mmc_host {
 	struct io_latency_state io_lat_s;
 #endif
 
+	bool sdr104_wa;
 	unsigned long		private[0] ____cacheline_aligned;
 };
 
@@ -728,6 +729,16 @@ static inline int mmc_host_uhs(struct mmc_host *host)
 		 MMC_CAP_UHS_DDR50);
 }
 
+static inline void mmc_host_clear_sdr104(struct mmc_host *host)
+{
+	host->caps &= ~MMC_CAP_UHS_SDR104;
+}
+
+static inline void mmc_host_set_sdr104(struct mmc_host *host)
+{
+	host->caps |= MMC_CAP_UHS_SDR104;
+}
+
 static inline int mmc_host_packed_wr(struct mmc_host *host)
 {
 	return host->caps2 & MMC_CAP2_PACKED_WR;