[PATCH V4] mmc: sdhci-msm: Update the software timeout value for sdhc

[Shaik Sajida Bhanu <sbhanu@codeaurora.org>]

Whenever SDHC run at clock rate 50MHZ or below, the hardware data
timeout value will be 21.47secs, which is approx. 22secs and we have
a current software timeout value as 10secs. We have to set software
timeout value more than the hardware data timeout value to avioid seeing
the below register dumps.

[  332.953670] mmc2: Timeout waiting for hardware interrupt.
[  332.959608] mmc2: sdhci: ============ SDHCI REGISTER DUMP ===========
[  332.966450] mmc2: sdhci: Sys addr:  0x00000000 | Version:  0x00007202
[  332.973256] mmc2: sdhci: Blk size:  0x00000200 | Blk cnt:  0x00000001
[  332.980054] mmc2: sdhci: Argument:  0x00000000 | Trn mode: 0x00000027
[  332.986864] mmc2: sdhci: Present:   0x01f801f6 | Host ctl: 0x0000001f
[  332.993671] mmc2: sdhci: Power:     0x00000001 | Blk gap:  0x00000000
[  333.000583] mmc2: sdhci: Wake-up:   0x00000000 | Clock:    0x00000007
[  333.007386] mmc2: sdhci: Timeout:   0x0000000e | Int stat: 0x00000000
[  333.014182] mmc2: sdhci: Int enab:  0x03ff100b | Sig enab: 0x03ff100b
[  333.020976] mmc2: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000
[  333.027771] mmc2: sdhci: Caps:      0x322dc8b2 | Caps_1:   0x0000808f
[  333.034561] mmc2: sdhci: Cmd:       0x0000183a | Max curr: 0x00000000
[  333.041359] mmc2: sdhci: Resp[0]:   0x00000900 | Resp[1]:  0x00000000
[  333.048157] mmc2: sdhci: Resp[2]:   0x00000000 | Resp[3]:  0x00000000
[  333.054945] mmc2: sdhci: Host ctl2: 0x00000000
[  333.059657] mmc2: sdhci: ADMA Err:  0x00000000 | ADMA Ptr:
0x0000000ffffff218
[  333.067178] mmc2: sdhci_msm: ----------- VENDOR REGISTER DUMP
-----------
[  333.074343] mmc2: sdhci_msm: DLL sts: 0x00000000 | DLL cfg:
0x6000642c | DLL cfg2: 0x0020a000
[  333.083417] mmc2: sdhci_msm: DLL cfg3: 0x00000000 | DLL usr ctl:
0x00000000 | DDR cfg: 0x80040873
[  333.092850] mmc2: sdhci_msm: Vndr func: 0x00008a9c | Vndr func2 :
0xf88218a8 Vndr func3: 0x02626040
[  333.102371] mmc2: sdhci: ============================================

So, set software timeout value more than hardware timeout value.

Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---

Changes since V3:
	- Addressed minor comments from Adrain Hunter and retained his
	  Acked-by Signed-off.

Changes since V2:
	- Updated 22 with 22LL to avoid compiler warning as
	  suggested by Adrian Hunter.
	- Added a check to update software data timeout value if its value
	  is less than the calculated hardware data timeout value as suggested
	  by Veerabhadrarao Badiganti.
Changes since V1:
	- Moved software data timeout update part to qcom specific file
	  as suggested by Veerabhadrarao Badiganti.
---
 drivers/mmc/host/sdhci-msm.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index e44b7a6..290a14c 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -2089,6 +2089,23 @@ static void sdhci_msm_cqe_disable(struct mmc_host *mmc, bool recovery)
 	sdhci_cqe_disable(mmc, recovery);
 }
 
+static void sdhci_msm_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
+{
+	u32 count, start = 15;
+
+	__sdhci_set_timeout(host, cmd);
+	count = sdhci_readb(host, SDHCI_TIMEOUT_CONTROL);
+	/*
+	 * Update software timeout value if its value is less than hardware data
+	 * timeout value. Qcom SoC hardware data timeout value was calculated
+	 * using 4 * MCLK * 2^(count + 13). where MCLK = 1 / host->clock.
+	 */
+	if (cmd && cmd->data && host->clock > 400000 &&
+	    host->clock <= 50000000 &&
+	    ((1 << (count + start)) > (10 * host->clock)))
+		host->data_timeout = 22LL * NSEC_PER_SEC;
+}
+
 static const struct cqhci_host_ops sdhci_msm_cqhci_ops = {
 	.enable		= sdhci_msm_cqe_enable,
 	.disable	= sdhci_msm_cqe_disable,
@@ -2438,6 +2455,7 @@ static const struct sdhci_ops sdhci_msm_ops = {
 	.irq	= sdhci_msm_cqe_irq,
 	.dump_vendor_regs = sdhci_msm_dump_vendor_regs,
 	.set_power = sdhci_set_power_noreg,
+	.set_timeout = sdhci_msm_set_timeout,
 };
 
 static const struct sdhci_pltfm_data sdhci_msm_pdata = {
-- 
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