Re: [PATCH v4 2/3] mmc: renesas_sdhi: skip SCC error check when retuning

2018-08-30 Thread Wolfram Sang
On Thu, Aug 30, 2018 at 01:32:06AM +0200, Niklas Söderlund wrote:
> From: Masaharu Hayakawa 
> 
> Checking for SCC error during retuning is unnecessary.
> 
> Signed-off-by: Masaharu Hayakawa 
> [Niklas: fix small style issue]
> Signed-off-by: Niklas Söderlund 

Reviewed-by: Wolfram Sang 
Tested-by: Wolfram Sang 



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[PATCH v4 2/3] mmc: renesas_sdhi: skip SCC error check when retuning

2018-08-29 Thread Niklas Söderlund
From: Masaharu Hayakawa 

Checking for SCC error during retuning is unnecessary.

Signed-off-by: Masaharu Hayakawa 
[Niklas: fix small style issue]
Signed-off-by: Niklas Söderlund 

---

* Changes since v3
- Use the newly introduce helper mmc_doing_retune() instead of checking
  host->mmc->doing_retune in the host driver.

* Changes since v2
- Add comment to describe why checking SCC errors when using 4 taps is
  not needed.

* Changes since v1
- Use intermediate variable use_4tap to simplify check.
---
 drivers/mmc/host/renesas_sdhi_core.c | 13 +
 1 file changed, 13 insertions(+)

diff --git a/drivers/mmc/host/renesas_sdhi_core.c 
b/drivers/mmc/host/renesas_sdhi_core.c
index c2c0e444cfc9f2dc..360777e9f35cbb3e 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -500,6 +500,19 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host 
*host)
 static bool renesas_sdhi_check_scc_error(struct tmio_mmc_host *host)
 {
struct renesas_sdhi *priv = host_to_priv(host);
+   bool use_4tap = host->pdata->flags & TMIO_MMC_HAVE_4TAP_HS400;
+
+   /*
+* Skip checking SCC errors when running on 4 taps in HS400 mode as
+* any retuning would still result in the same 4 taps being used.
+*/
+   if (!(host->mmc->ios.timing == MMC_TIMING_UHS_SDR104) &&
+   !(host->mmc->ios.timing == MMC_TIMING_MMC_HS200) &&
+   !(host->mmc->ios.timing == MMC_TIMING_MMC_HS400 && !use_4tap))
+   return false;
+
+   if (mmc_doing_retune(host->mmc))
+   return false;
 
/* Check SCC error */
if (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL) &
-- 
2.18.0