From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ernst.netinsight.se ([194.16.221.21]) by bombadil.infradead.org with smtp (Exim 4.69 #1 (Red Hat Linux)) id 1OE45v-0001kg-T8 for linux-mtd@lists.infradead.org; Mon, 17 May 2010 17:27:12 +0000 Message-ID: <4BF17C5D.1020501@netinsight.net> Date: Mon, 17 May 2010 19:26:53 +0200 From: =?UTF-8?B?QW5kZXJzIEdyYWZzdHLDtm0=?= MIME-Version: 1.0 To: David Woodhouse Subject: Re: [PATCH] mtd: cfi_cmdset_0001: Fix max timeout for locking operations References: <4B8834FB.2070004@netinsight.net> <1273792018.9999.268.camel@macbook.infradead.org> In-Reply-To: <1273792018.9999.268.camel@macbook.infradead.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Linux-MTD Mailing List List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 2010-05-14 01:06, David Woodhouse wrote: > On Fri, 2010-02-26 at 21:54 +0100, Anders Grafström wrote: >> The max timeout is currently too short for some flash chips. >> This patch increases it to 10 seconds. The typical timeout >> remains unchanged (the tick period, 1000000/HZ). >> >> Specification change #11 in '5 Volt Intel StrataFlash Memory Specification Update' >> (297848-15) specifies an increase of Clear Block Lock-Bit Time Max to 7 sec. >> This is contradicted by the table in Specification Change #8 which says .70 sec >> but a 10 sec timeout doesn't hurt so play it safe. >> >> Signed-off-by: Anders Grafström >> --- >> drivers/mtd/chips/cfi_cmdset_0001.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c >> index 9253043..83e4ae2 100644 >> --- a/drivers/mtd/chips/cfi_cmdset_0001.c >> +++ b/drivers/mtd/chips/cfi_cmdset_0001.c >> @@ -2077,7 +2077,7 @@ static int __xipram do_xxlock_oneblock(struct map_info *map, struct flchip *chip >> */ >> udelay = (!extp || !(extp->FeatureSupport & (1 << 5))) ? 1000000/HZ : 0; >> >> - ret = WAIT_TIMEOUT(map, chip, adr, udelay, udelay * 100); >> + ret = WAIT_TIMEOUT(map, chip, adr, udelay, udelay * HZ * 10); > > I don't see how this makes any sense. What is the _unit_ of the argument > you're changing? Is it µs, is it ticks? You aren't just changing the > value here; you're actually changing the units. The dimensional analysis > doesn't make sense. > > AFAICT this really is supposed to be µs, so multiplying by HZ has to be > wrong. Hm, I make it: udelay: 1000000 / HZ = (µs/s) / (ticks/s) = µs/ticks udelay_max (before): udelay * 100 = (µs/ticks) * ticks = µs udelay_max (after): udelay * HZ * 10 = (µs/ticks) * (ticks/s) * s = µs Here's a re-spin, with less HZ involvement: >>From 0ecd111a5cdc37631fa307d85e497075c467a82f Mon Sep 17 00:00:00 2001 From: Anders Grafström Date: Mon, 17 May 2010 15:23:08 +0200 Subject: [PATCH] mtd: cfi_cmdset_0001: Fix timeout for locking operations The lock/unlock timeout is currently way too short for some flash chips. This patch increases it to 10 seconds. The typical delay remains unchanged. Specification change #11 in '5 Volt Intel StrataFlash Memory Specification Update' (297848-15) specifies an increase of Clear Block Lock-Bit Time Max to 7 sec. This is contradicted by the table in Specification Change #8 which says .70 sec but a 10 sec timeout doesn't hurt so play it safe. Signed-off-by: Anders Grafström --- drivers/mtd/chips/cfi_cmdset_0001.c | 14 +++++++++----- 1 files changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c index 62f3ea9..3a22f47 100644 --- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -2045,7 +2045,8 @@ static int __xipram do_xxlock_oneblock(struct map_info *map, struct flchip *chip { struct cfi_private *cfi = map->fldrv_priv; struct cfi_pri_intelext *extp = cfi->cmdset_priv; - int udelay; + unsigned int udelay = 0; + unsigned int udelay_max = 0; int ret; adr += chip->start; @@ -2071,12 +2072,15 @@ static int __xipram do_xxlock_oneblock(struct map_info *map, struct flchip *chip BUG(); /* - * If Instant Individual Block Locking supported then no need - * to delay. + * If Instant Individual Block Locking is unsupported then use + * the tick period as the typical delay and 10 seconds for the timeout. */ - udelay = (!extp || !(extp->FeatureSupport & (1 << 5))) ? 1000000/HZ : 0; + if (!extp || !(extp->FeatureSupport & (1 << 5))) { + udelay = 1000000 / HZ; + udelay_max = 10000000; + } - ret = WAIT_TIMEOUT(map, chip, adr, udelay, udelay * 100); + ret = WAIT_TIMEOUT(map, chip, adr, udelay, udelay_max); if (ret) { map_write(map, CMD(0x70), adr); chip->state = FL_STATUS; -- 1.7.1