[prev in list] [next in list] [prev in thread] [next in thread] 

List:       linux-mmc
Subject:    + sdhci-of-cleanup-esdhcs-set_clock-a-little-bit.patch added to -mm tree
From:       akpm () linux-foundation ! org
Date:       2009-08-17 23:09:14
Message-ID: 200908172309.n7HN9FbQ015024 () imap1 ! linux-foundation ! org
[Download RAW message or body]


The patch titled
     sdhci-of: cleanup eSDHC's set_clock() a little bit
has been added to the -mm tree.  Its filename is
     sdhci-of-cleanup-esdhcs-set_clock-a-little-bit.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this

The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/

------------------------------------------------------
Subject: sdhci-of: cleanup eSDHC's set_clock() a little bit
From: Anton Vorontsov <avorontsov@ru.mvista.com>

- Get rid of incomprehensible "if { for { if } }" construction for the
  exponential divisor calculation. The first if statement isn't correct
  at all, since it should check for "host->max_clk / pre_div / 16 >
  clock". The error doesn't cause any bugs because the check in the for
  loop does the right thing, and so the outer check becomes useless;

- For the linear divisor do the same: a single while statement is more
  readable than for + if construction;

- Add dev_dbg() that prints desired and actual clock frequency.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: David Vrabel <david.vrabel@csr.com>
Cc: Ben Dooks <ben@fluff.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/mmc/host/sdhci-of.c |   19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff -puN drivers/mmc/host/sdhci-of.c~sdhci-of-cleanup-esdhcs-set_clock-a-little-bit \
                drivers/mmc/host/sdhci-of.c
--- a/drivers/mmc/host/sdhci-of.c~sdhci-of-cleanup-esdhcs-set_clock-a-little-bit
+++ a/drivers/mmc/host/sdhci-of.c
@@ -121,8 +121,8 @@ static void esdhc_writeb(struct sdhci_ho
 
 static void esdhc_set_clock(struct sdhci_host *host, unsigned int clock)
 {
-	int div;
 	int pre_div = 2;
+	int div = 1;
 
 	clrbits32(host->ioaddr + ESDHC_SYSTEM_CONTROL, ESDHC_CLOCK_IPGEN |
 		  ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN | ESDHC_CLOCK_MASK);
@@ -130,17 +130,14 @@ static void esdhc_set_clock(struct sdhci
 	if (clock == 0)
 		goto out;
 
-	if (host->max_clk / 16 > clock) {
-		for (; pre_div < 256; pre_div *= 2) {
-			if (host->max_clk / pre_div < clock * 16)
-				break;
-		}
-	}
+	while (host->max_clk / pre_div / 16 > clock && pre_div < 256)
+		pre_div *= 2;
 
-	for (div = 1; div <= 16; div++) {
-		if (host->max_clk / (div * pre_div) <= clock)
-			break;
-	}
+	while (host->max_clk / pre_div / div > clock && div < 16)
+		div++;
+
+	dev_dbg(mmc_dev(host->mmc), "desired SD clock: %d, actual: %d\n",
+		clock, host->max_clk / pre_div / div);
 
 	pre_div >>= 1;
 	div--;
_

Patches currently in -mm which might be from avorontsov@ru.mvista.com are

linux-next.patch
mtd-sst25l-non-jedec-spi-flash-driver.patch
mtd-m25p80-fix-null-pointer-dereference-bug.patch
sdhci-be-more-strict-with-get_min_clock-usage.patch
sdhci-of-fix-sd-clock-calculation.patch
sdhci-of-avoid-writing-reserved-bits-into-host-control-register.patch
sdhci-of-fix-high-speed-cards-recognition.patch
powerpc-introduce-and-document-sdhciwp-inverted-property-for-esdhc.patch
sdhci-of-dont-hard-code-inverted-write-protect-quirk.patch
sdhci-of-cleanup-esdhcs-set_clock-a-little-bit.patch
powerpc-85xx-add-esdhc-support-for-mpc8536ds-boards.patch
spi-add-support-for-device-table-matching.patch
mtd-m25p80-convert-to-device-table-matching.patch
of-remove-stmm25p40-alias.patch
hwmon-adxx-convert-to-device-table-matching.patch
hwmon-lm70-convert-to-device-table-matching.patch
spi-prefix-modalias-with-spi.patch

--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[prev in list] [next in list] [prev in thread] [next in thread]