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From: chitranshmandhaniya@gmail.com
To: hansg@kernel.org, ilpo.jarvinen@linux.intel.com
Cc: platform-driver-x86@vger.kernel.org,
	linux-kernel@vger.kernel.org, Chitransh_Mandhaniya@dell.com
Subject: [PATCH v2 0/2] platform/x86: dell-uart-backlight: recover from stray EC response byte
Date: Thu, 15 Oct 2026 13:13:37 +0530	[thread overview]
Message-ID: <20261015074339.27388-1-chitranshmandhaniya@gmail.com> (raw)
In-Reply-To: <20261004110333.5790-1-chitranshmandhaniya@gmail.com>

From: Chitransh Mandhaniya <Chitransh_Mandhaniya@dell.com>

On some Dell AIO machines the EC occasionally inserts a spurious byte
after the cmd-echo in UART backlight response frames, causing checksum
mismatches and -EIO.

Patch 1 extracts the response parsing into a dell_uart_bl_receive_data()
helper so it can be called again after resyncing.

Patch 2 adds the stray byte recovery: on checksum mismatch, drop the
byte at the first payload position, shift data down, and call the helper
again to re-fetch the checksum byte from the wire.

v1 -> v2:
  - Extract dell_uart_bl_receive_data() helper instead of using a
    for-loop with pass counter, call it again after resync (Ilpo)
  - Split into two patches: refactor + feature (Ilpo)

Chitransh Mandhaniya (2):
  platform/x86: dell-uart-backlight: extract dell_uart_bl_receive_data()
    helper
  platform/x86: dell-uart-backlight: recover from stray EC response byte

 .../platform/x86/dell/dell-uart-backlight.c   | 63 ++++++++++++++-----
 1 file changed, 48 insertions(+), 15 deletions(-)

-- 
2.43.0


  parent reply	other threads:[~2026-10-15  7:44 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-04 11:03 [PATCH] platform/x86: dell-uart-backlight: recover from stray EC response byte chitranshmandhaniya
2026-10-14 11:50 ` Ilpo Järvinen
2026-10-15  7:43 ` chitranshmandhaniya [this message]
2026-10-15  7:43   ` [PATCH v2 1/2] platform/x86: dell-uart-backlight: extract dell_uart_bl_receive_data() helper chitranshmandhaniya
2026-10-15  7:43   ` [PATCH v2 2/2] platform/x86: dell-uart-backlight: recover from stray EC response byte chitranshmandhaniya
2026-10-15 10:12     ` Ilpo Järvinen
2026-10-15 10:24     ` Ilpo Järvinen

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