From: Arnd Bergmann <arnd@kernel.org>
To: Hugues Fruchet <hugues.fruchet@foss.st.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Peter Griffin <peter.griffin@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] st-delta: avoid excessive stack usage
Date: Tue, 10 Jun 2025 11:31:56 +0200 [thread overview]
Message-ID: <20250610093201.2645325-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
Building with a reduced stack warning limit shows that delta_mjpeg_decode()
copies a giant structure to the stack each time but only uses three of
its members:
drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c: In function 'delta_mjpeg_decode':
drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c:427:1: error: the frame size of 1296 bytes is larger than 1280 bytes [-Werror=frame-larger-than=]
Open-code the passing of the structure members that are actually used here.
Fixes: 433ff5b4a29b ("[media] st-delta: add mjpeg support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
.../platform/st/sti/delta/delta-mjpeg-dec.c | 20 ++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c b/drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c
index 0533d4a083d2..a078f1107300 100644
--- a/drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c
+++ b/drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c
@@ -239,7 +239,7 @@ static int delta_mjpeg_ipc_open(struct delta_ctx *pctx)
return 0;
}
-static int delta_mjpeg_ipc_decode(struct delta_ctx *pctx, struct delta_au *au)
+static int delta_mjpeg_ipc_decode(struct delta_ctx *pctx, dma_addr_t pstart, dma_addr_t pend)
{
struct delta_dev *delta = pctx->dev;
struct delta_mjpeg_ctx *ctx = to_ctx(pctx);
@@ -256,8 +256,8 @@ static int delta_mjpeg_ipc_decode(struct delta_ctx *pctx, struct delta_au *au)
memset(params, 0, sizeof(*params));
- params->picture_start_addr_p = (u32)(au->paddr);
- params->picture_end_addr_p = (u32)(au->paddr + au->size - 1);
+ params->picture_start_addr_p = pstart;
+ params->picture_end_addr_p = pend;
/*
* !WARNING!
@@ -374,12 +374,14 @@ static int delta_mjpeg_decode(struct delta_ctx *pctx, struct delta_au *pau)
struct delta_dev *delta = pctx->dev;
struct delta_mjpeg_ctx *ctx = to_ctx(pctx);
int ret;
- struct delta_au au = *pau;
+ void *au_vaddr = pau->vaddr;
+ dma_addr_t au_dma = pau->paddr;
+ size_t au_size = pau->size;
unsigned int data_offset = 0;
struct mjpeg_header *header = &ctx->header_struct;
if (!ctx->header) {
- ret = delta_mjpeg_read_header(pctx, au.vaddr, au.size,
+ ret = delta_mjpeg_read_header(pctx, au_vaddr, au_size,
header, &data_offset);
if (ret) {
pctx->stream_errors++;
@@ -405,17 +407,17 @@ static int delta_mjpeg_decode(struct delta_ctx *pctx, struct delta_au *pau)
goto err;
}
- ret = delta_mjpeg_read_header(pctx, au.vaddr, au.size,
+ ret = delta_mjpeg_read_header(pctx, au_vaddr, au_size,
ctx->header, &data_offset);
if (ret) {
pctx->stream_errors++;
goto err;
}
- au.paddr += data_offset;
- au.vaddr += data_offset;
+ au_dma += data_offset;
+ au_vaddr += data_offset;
- ret = delta_mjpeg_ipc_decode(pctx, &au);
+ ret = delta_mjpeg_ipc_decode(pctx, au_dma, au_dma + au_size - 1);
if (ret)
goto err;
--
2.39.5
reply other threads:[~2025-06-10 9:32 UTC|newest]
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