This is a note to let you know that I've just added the patch titled
ALSA: emu10k1: make E-MU FPGA writes potentially more reliable
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-emu10k1-make-e-mu-fpga-writes-potentially-more-.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4bf983d5ac7c3fd8ac18932290f120e2f0012cd8
Author: Oswald Buddenhagen <oswald.buddenhagen@xxxxxx>
Date: Sun Apr 28 11:37:16 2024 +0200
ALSA: emu10k1: make E-MU FPGA writes potentially more reliable
[ Upstream commit 15c7e87aa88f0ab2d51c2e2123b127a6d693ca21 ]
We did not delay after the second strobe signal, so another immediately
following access could potentially corrupt the written value.
This is a purely speculative fix with no supporting evidence, but after
taking out the spinlocks around the writes, it seems plausible that a
modern processor could be actually too fast. Also, it's just cleaner to
be consistent.
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@xxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Message-ID: <20240428093716.3198666-7-oswald.buddenhagen@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/pci/emu10k1/io.c b/sound/pci/emu10k1/io.c
index 74df2330015f6..5cb8acf5b158c 100644
--- a/sound/pci/emu10k1/io.c
+++ b/sound/pci/emu10k1/io.c
@@ -285,6 +285,7 @@ static void snd_emu1010_fpga_write_locked(struct snd_emu10k1 *emu, u32 reg, u32
outw(value, emu->port + A_GPIO);
udelay(10);
outw(value | 0x80 , emu->port + A_GPIO); /* High bit clocks the value into the fpga. */
+ udelay(10);
}
void snd_emu1010_fpga_write(struct snd_emu10k1 *emu, u32 reg, u32 value)
