Numonyx NOR and chip->mutex bug?

[Stefan Bigler]

Hi Mike

I attached a patch for you adding some printk, with those already the 
creation of the first ubivolume goes wrong.
Is this also the case in your setup?

Regards Stefan

Subject: [PATCH 2/2] MTD: cfi_cmdset_0001 driver add tracing

This tracing force in my case a race condition. When I create
a ubivolume.

Signed-off-by: Stefan Bigler <stefan.bigler at keymile.com>
---
  drivers/mtd/chips/cfi_cmdset_0001.c |   15 +++++++++++++++
  1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c 
b/drivers/mtd/chips/cfi_cmdset_0001.c
index d3b2cd3..ea59726 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -37,6 +37,8 @@
  #include <linux/mtd/compatmac.h>
  #include <linux/mtd/cfi.h>

+#include <linux/syscalls.h>
+
  /* #define CMDSET0001_DISABLE_ERASE_SUSPEND_ON_WRITE */
  /* #define CMDSET0001_DISABLE_WRITE_SUSPEND */

@@ -799,6 +801,8 @@ static int chip_ready (struct map_info *map, struct 
flchip *chip, unsigned long

          /* Erase suspend */
          map_write(map, CMD(0xB0), adr);
+        printk("[%10u][%04ld] erase suspend 1         adr=0x%08lx\n",
+               jiffies_to_usecs(jiffies)/1000, sys_gettid(), adr);

          /* If the flash has finished erasing, then 'erase suspend'
           * appears to make some (28F320) flash devices switch to
@@ -1012,6 +1016,10 @@ static void put_chip(struct map_info *map, struct 
flchip *chip, unsigned long ad
             do. */
          map_write(map, CMD(0xd0), adr);
          map_write(map, CMD(0x70), adr);
+
+        printk("[%10u][%04ld] erase resumed 2b        adr=0x%08lx\n",
+               jiffies_to_usecs(jiffies)/1000, sys_gettid(), adr);
+
          chip->oldstate = FL_READY;
          chip->state = FL_ERASING;
          break;
@@ -1884,6 +1892,10 @@ static int __xipram do_erase_oneblock(struct 
map_info *map, struct flchip *chip,
   retry:
      mutex_lock(&chip->mutex);
      ret = get_chip(map, chip, adr, FL_ERASING);
+
+    printk("[%10u][%04ld] do_erase_oneblock start adr=0x%08lx len=0x%x\n",
+           jiffies_to_usecs(jiffies)/1000, sys_gettid(), adr, len);
+
      if (ret) {
          mutex_unlock(&chip->mutex);
          return ret;
@@ -1953,6 +1965,9 @@ static int __xipram do_erase_oneblock(struct 
map_info *map, struct flchip *chip,

      xip_enable(map, chip, adr);
   out:    put_chip(map, chip, adr);
+    printk("[%10u][%04ld] do_erase_oneblock end   adr=0x%08lx len=0x%x 
\n",
+        jiffies_to_usecs(jiffies)/1000, sys_gettid(), adr, len);
+
      mutex_unlock(&chip->mutex);
      return ret;
  }
-- 
1.7.0.5

Am 02/07/2011 05:46 PM, schrieb Michael Cashwell:
> On Feb 7, 2011, at 11:22 AM, Joakim Tjernlund wrote:
>
>> Michael Cashwell<mboards at prograde.net>  wrote on 2011/02/07 16:46:22:
>>
>>> My current workaround from my problem is to do a throw-away status read "(void) map_read(map, addr);" after that 0x50, 0xd0, 0x70 sequence. Since no one else is seeing my problem I expect it's some issue with my specific batch of chips. Ugh.
>>
>> Possibly, or an accident waiting to happen to the rest of us.
>
> That does worry me too.
>
>> The map_read will probably force some HW completion. Perhaps some sync() op. will do the same? Just to nail it down.
>
> Once your patch is handled I will continue to try to fully explain my issue. I'm not giving up yet.
>
>> BTW, do you have CONFIG_MTD_COMPLEX_MAPPINGS=y ? I do
>
> Interesting. I have used that on a different platform where some of the high-order address lines were GPIOs.
>
> But no, I'm not using that in this case. Just a simple linear mapping of the whole part.
>
> -Mike
>