media: si2157: Fix "warm" tuner state detection
authorRobert Schlabbach <robert_s@gmx.net>
Wed, 1 Dec 2021 21:08:43 +0000 (22:08 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Jan 2022 09:53:54 +0000 (10:53 +0100)
commitb4b911b1648cb8c4871c92d9e9b3c90d3e5ae7ae
tree31285883f43f0585e148338f1b2a3dde4696d1c3
parent7009a5fbc589484c1b6e6e5ed1c47b64b62c5769
media: si2157: Fix "warm" tuner state detection

[ Upstream commit a6441ea29cb2c9314654e093a1cd8020b9b851c8 ]

Commit e955f959ac52 ("media: si2157: Better check for running tuner in
init") completely broke the "warm" tuner detection of the si2157 driver
due to a simple endian error: The Si2157 CRYSTAL_TRIM property code is
0x0402 and needs to be transmitted LSB first. However, it was inserted
MSB first, causing the warm detection to always fail and spam the kernel
log with tuner initialization messages each time the DVB frontend
device was closed and reopened:

[  312.215682] si2157 16-0060: found a 'Silicon Labs Si2157-A30'
[  312.264334] si2157 16-0060: firmware version: 3.0.5
[  342.248593] si2157 16-0060: found a 'Silicon Labs Si2157-A30'
[  342.295743] si2157 16-0060: firmware version: 3.0.5
[  372.328574] si2157 16-0060: found a 'Silicon Labs Si2157-A30'
[  372.385035] si2157 16-0060: firmware version: 3.0.5

Also, the reinitializations were observed disturb _other_ tuners on
multi-tuner cards such as the Hauppauge WinTV-QuadHD, leading to missed
or errored packets when one of the other DVB frontend devices on that
card was opened.

Fix the order of the property code bytes to make the warm detection work
again, also reducing the tuner initialization message in the kernel log
to once per power-on, as well as fixing the interference with other
tuners.

Link: https://lore.kernel.org/linux-media/trinity-2a86eb9d-6264-4387-95e1-ba7b79a4050f-1638392923493@3c-app-gmx-bap03
Fixes: e955f959ac52 ("media: si2157: Better check for running tuner in init")
Reported-by: Robert Schlabbach <robert_s@gmx.net>
Signed-off-by: Robert Schlabbach <robert_s@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/media/tuners/si2157.c