FAILED: patch "[PATCH] spi: s3c64xx: fix NULL-deref on driver unbind" failed to apply to 6.1-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 45daacbead8a009844bd5dba6cfa731332184d17
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026051226-composure-saffron-d0fa@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 45daacbead8a009844bd5dba6cfa731332184d17 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Fri, 10 Apr 2026 11:49:25 +0200
Subject: [PATCH] spi: s3c64xx: fix NULL-deref on driver unbind

A change moving DMA channel allocation from probe() back to
s3c64xx_spi_prepare_transfer() failed to remove the corresponding
deallocation from remove().

Drop the bogus DMA channel release from remove() to avoid triggering a
NULL-pointer dereference on driver unbind.

This issue was flagged by Sashiko when reviewing a controller
deregistration fix.

Fixes: f52b03c70744 ("spi: s3c64xx: requests spi-dma channel only during data transfer")
Cc: stable@vger.kernel.org	# 6.0
Cc: Adithya K V <adithya.kv@samsung.com>
Link: https://sashiko.dev/#/patchset/20260410081757.503099-1-johan%40kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260410094925.518343-1-johan@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 95b61264b679..37176e557099 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1403,11 +1403,6 @@ static void s3c64xx_spi_remove(struct platform_device *pdev)
 
 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
 
-	if (!is_polling(sdd)) {
-		dma_release_channel(sdd->rx_dma.ch);
-		dma_release_channel(sdd->tx_dma.ch);
-	}
-
 	pm_runtime_put_noidle(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);