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Thu, 19 Mar 2026 04:54:18 -0700 (PDT) Received: from localhost.localdomain ([149.102.251.98]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-2c0e536896csm8384630eec.3.2026.03.19.04.54.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Mar 2026 04:54:17 -0700 (PDT) From: Gabriel Rondon To: parthiban.veerasooran@microchip.com, christian.gromm@microchip.com, gregkh@linuxfoundation.org Cc: linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH] staging: most: dim2: replace BUG_ON() with graceful error handling Date: Thu, 19 Mar 2026 11:54:08 +0000 Message-Id: <20260319115408.24215-1-grondon@gmail.com> X-Mailer: git-send-email 2.33.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" BUG_ON() is deprecated as it crashes the entire kernel on assertion failure (see Documentation/process/deprecated.rst). Replace all BUG_ON() calls in dim2.c with proper error handling that returns appropriate error codes instead of panicking. In try_start_dim_transfer(), replace the BUG_ON for null/uninitialized channel with an early return of -EINVAL, and replace the BUG_ON for zero bus_address with an error return that properly releases the spinlock first. In service_done_flag(), replace BUG_ON with an early return since the function returns void. In configure_channel(), enqueue(), and poison_channel(), replace BUG_ON range checks on ch_idx with returns of -EINVAL. Signed-off-by: Gabriel Rondon --- drivers/staging/most/dim2/dim2.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/d= im2.c index 8d649d920..06f4252a8 100644 --- a/drivers/staging/most/dim2/dim2.c +++ b/drivers/staging/most/dim2/dim2.c @@ -168,8 +168,8 @@ static int try_start_dim_transfer(struct hdm_channel *h= dm_ch) unsigned long flags; struct dim_ch_state st; =20 - BUG_ON(!hdm_ch); - BUG_ON(!hdm_ch->is_initialized); + if (!hdm_ch || !hdm_ch->is_initialized) + return -EINVAL; =20 spin_lock_irqsave(&dim_lock, flags); if (list_empty(head)) { @@ -190,7 +190,10 @@ static int try_start_dim_transfer(struct hdm_channel *= hdm_ch) return -EAGAIN; } =20 - BUG_ON(mbo->bus_address =3D=3D 0); + if (mbo->bus_address =3D=3D 0) { + spin_unlock_irqrestore(&dim_lock, flags); + return -EFAULT; + } if (!dim_enqueue_buffer(&hdm_ch->ch, mbo->bus_address, buf_size)) { list_del(head->next); spin_unlock_irqrestore(&dim_lock, flags); @@ -271,8 +274,8 @@ static void service_done_flag(struct dim2_hdm *dev, int= ch_idx) unsigned long flags; u8 *data; =20 - BUG_ON(!hdm_ch); - BUG_ON(!hdm_ch->is_initialized); + if (!hdm_ch || !hdm_ch->is_initialized) + return; =20 spin_lock_irqsave(&dim_lock, flags); =20 @@ -457,7 +460,8 @@ static int configure_channel(struct most_interface *mos= t_iface, int ch_idx, int const ch_addr =3D ch_idx * 2 + 2; struct hdm_channel *const hdm_ch =3D dev->hch + ch_idx; =20 - BUG_ON(ch_idx < 0 || ch_idx >=3D DMA_CHANNELS); + if (ch_idx < 0 || ch_idx >=3D DMA_CHANNELS) + return -EINVAL; =20 if (hdm_ch->is_initialized) return -EPERM; @@ -569,7 +573,8 @@ static int enqueue(struct most_interface *most_iface, i= nt ch_idx, struct hdm_channel *hdm_ch =3D dev->hch + ch_idx; unsigned long flags; =20 - BUG_ON(ch_idx < 0 || ch_idx >=3D DMA_CHANNELS); + if (ch_idx < 0 || ch_idx >=3D DMA_CHANNELS) + return -EINVAL; =20 if (!hdm_ch->is_initialized) return -EPERM; @@ -645,7 +650,8 @@ static int poison_channel(struct most_interface *most_i= face, int ch_idx) u8 hal_ret; int ret =3D 0; =20 - BUG_ON(ch_idx < 0 || ch_idx >=3D DMA_CHANNELS); + if (ch_idx < 0 || ch_idx >=3D DMA_CHANNELS) + return -EINVAL; =20 if (!hdm_ch->is_initialized) return -EPERM; --=20 2.33.0