At Mon, 27 Aug 2012 22:25:21 -0400, David Flater wrote:

v2: Fixed result still wrong in the case of 512 KiB DRAM. Oops.

Applicable to 3.5.3 mainline.

In emu8000.c, size_dram determines the amount of memory on the sound card by doing write/readback tests starting at 512 KiB and incrementing by 512 KiB. On success, detected_size is updated to the successful address and testing continues. On failure, the loop is immediately exited. The resulting detected_size is 512 KiB too small except in two special cases:

1. If there is no memory, the initial 0 value of detected_size is used, which is correct.
2. If the address space wraps around, detected_size is updated before the bailout, so the result is correct.

The patch corrects all cases and was tested with an AWE64 Gold. Before: EMU8000 [0x620]: 3584 Kb on-board memory detected asfxload 4GMGSMT.SF2 (4174814 B) fails. After: EMU8000 [0x620]: 4096 Kb on-board memory detected asfxload 4GMGSMT.SF2 succeeds.

I do not have a card with 512 KiB to test with, but by forcibly enabling the added conditional I verified on the AWE64 Gold that it detects 512 KiB (successfully reading from the first memory location) and does not hang the card.

C.f. Bug 46451 https://bugzilla.kernel.org/show_bug.cgi?id=46451

Signed-off-by: David Flater dave@flaterco.com

Thanks, applied.

Takashi

---

--- linux-3.5.3-nameless/sound/isa/sb/emu8000.c.orig 2012-08-25 22:32:13.000000000 -0400 +++ linux-3.5.3-nameless/sound/isa/sb/emu8000.c 2012-08-27 22:06:15.729510037 -0400 @@ -417,9 +417,6 @@ size_dram(struct snd_emu8000 *emu) EMU8000_SMLD_READ(emu); /* discard stale data */ if (EMU8000_SMLD_READ(emu) != UNIQUE_ID2) break; /* no memory at this address */

• detected_size = size;
  

• snd_emu8000_read_wait(emu);

  /*

@@ -432,6 +429,18 @@ size_dram(struct snd_emu8000 *emu) if (EMU8000_SMLD_READ(emu) != UNIQUE_ID1) break; /* we must have wrapped around */ snd_emu8000_read_wait(emu);

• /* Otherwise, it's valid memory. */
  

• detected_size = size + 512 * 1024;
  

• }

• /* Distinguish 512 KiB from 0. */

• if (detected_size == 0) {

• snd_emu8000_read_wait(emu);
  

• EMU8000_SMALR_WRITE(emu, EMU8000_DRAM_OFFSET);
  

• EMU8000_SMLD_READ(emu); /* discard stale data  */
  

• if (EMU8000_SMLD_READ(emu) == UNIQUE_ID1)
  

• 	detected_size = 512 * 1024;
  

  }

  /* wait until FULL bit in SMAxW register is false */

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