* [PATCH] media: vidtv: Use crc32_be() instead of open coding
@ 2026-03-16 21:15 Eric Biggers
2026-03-17 11:06 ` Ard Biesheuvel
0 siblings, 1 reply; 2+ messages in thread
From: Eric Biggers @ 2026-03-16 21:15 UTC (permalink / raw)
To: Daniel W . S . Almeida, Mauro Carvalho Chehab, linux-media
Cc: linux-kernel, Ard Biesheuvel, Eric Biggers
dvb_crc32() does exactly the same computation as the crc32_be() library
function. Just call crc32_be() instead.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
drivers/media/test-drivers/vidtv/Kconfig | 1 +
drivers/media/test-drivers/vidtv/vidtv_psi.c | 57 +-------------------
2 files changed, 2 insertions(+), 56 deletions(-)
diff --git a/drivers/media/test-drivers/vidtv/Kconfig b/drivers/media/test-drivers/vidtv/Kconfig
index e511e51c0b5b..8cb10b75603b 100644
--- a/drivers/media/test-drivers/vidtv/Kconfig
+++ b/drivers/media/test-drivers/vidtv/Kconfig
@@ -1,9 +1,10 @@
# SPDX-License-Identifier: GPL-2.0-only
config DVB_VIDTV
tristate "Virtual DVB Driver (vidtv)"
depends on DVB_CORE && MEDIA_SUPPORT && I2C
+ select CRC32
help
The virtual DVB test driver serves as a reference DVB driver and helps
validate the existing APIs in the media subsystem. It can also aid developers
working on userspace applications.
diff --git a/drivers/media/test-drivers/vidtv/vidtv_psi.c b/drivers/media/test-drivers/vidtv/vidtv_psi.c
index 685a1f7b2fb1..1b6225d65ef3 100644
--- a/drivers/media/test-drivers/vidtv/vidtv_psi.c
+++ b/drivers/media/test-drivers/vidtv/vidtv_psi.c
@@ -29,65 +29,10 @@
#define CRC_SIZE_IN_BYTES 4
#define MAX_VERSION_NUM 32
#define INITIAL_CRC 0xffffffff
#define ISO_LANGUAGE_CODE_LEN 3
-static const u32 CRC_LUT[256] = {
- /* from libdvbv5 */
- 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
- 0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
- 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
- 0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
- 0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
- 0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
- 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
- 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
- 0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
- 0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
- 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
- 0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
- 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
- 0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
- 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
- 0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
- 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
- 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
- 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
- 0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
- 0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
- 0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
- 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
- 0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
- 0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
- 0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
- 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
- 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
- 0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
- 0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
- 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
- 0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
- 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
- 0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
- 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
- 0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
- 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
- 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
- 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
- 0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
- 0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
- 0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
- 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
-};
-
-static u32 dvb_crc32(u32 crc, u8 *data, u32 len)
-{
- /* from libdvbv5 */
- while (len--)
- crc = (crc << 8) ^ CRC_LUT[((crc >> 24) ^ *data++) & 0xff];
- return crc;
-}
-
static void vidtv_psi_update_version_num(struct vidtv_psi_table_header *h)
{
h->version++;
}
@@ -173,11 +118,11 @@ static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args *args)
if (!args->crc && !args->is_crc)
pr_warn_ratelimited("Missing CRC for chunk\n");
if (args->crc)
- *args->crc = dvb_crc32(*args->crc, args->from, args->len);
+ *args->crc = crc32_be(*args->crc, args->from, args->len);
if (args->new_psi_section && !aligned) {
pr_warn_ratelimited("Cannot write a new PSI section in a misaligned buffer\n");
/* forcibly align and hope for the best */
base-commit: 2d1373e4246da3b58e1df058374ed6b101804e07
--
2.53.0
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] media: vidtv: Use crc32_be() instead of open coding
2026-03-16 21:15 [PATCH] media: vidtv: Use crc32_be() instead of open coding Eric Biggers
@ 2026-03-17 11:06 ` Ard Biesheuvel
0 siblings, 0 replies; 2+ messages in thread
From: Ard Biesheuvel @ 2026-03-17 11:06 UTC (permalink / raw)
To: Eric Biggers, Daniel W . S . Almeida, Mauro Carvalho Chehab,
linux-media
Cc: linux-kernel
On Mon, 16 Mar 2026, at 22:15, Eric Biggers wrote:
> dvb_crc32() does exactly the same computation as the crc32_be() library
> function. Just call crc32_be() instead.
>
> Signed-off-by: Eric Biggers <ebiggers@kernel.org>
> ---
> drivers/media/test-drivers/vidtv/Kconfig | 1 +
> drivers/media/test-drivers/vidtv/vidtv_psi.c | 57 +-------------------
> 2 files changed, 2 insertions(+), 56 deletions(-)
>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
> diff --git a/drivers/media/test-drivers/vidtv/Kconfig
> b/drivers/media/test-drivers/vidtv/Kconfig
> index e511e51c0b5b..8cb10b75603b 100644
> --- a/drivers/media/test-drivers/vidtv/Kconfig
> +++ b/drivers/media/test-drivers/vidtv/Kconfig
> @@ -1,9 +1,10 @@
> # SPDX-License-Identifier: GPL-2.0-only
> config DVB_VIDTV
> tristate "Virtual DVB Driver (vidtv)"
> depends on DVB_CORE && MEDIA_SUPPORT && I2C
> + select CRC32
> help
> The virtual DVB test driver serves as a reference DVB driver and
> helps
> validate the existing APIs in the media subsystem. It can also aid
> developers
> working on userspace applications.
>
> diff --git a/drivers/media/test-drivers/vidtv/vidtv_psi.c
> b/drivers/media/test-drivers/vidtv/vidtv_psi.c
> index 685a1f7b2fb1..1b6225d65ef3 100644
> --- a/drivers/media/test-drivers/vidtv/vidtv_psi.c
> +++ b/drivers/media/test-drivers/vidtv/vidtv_psi.c
> @@ -29,65 +29,10 @@
> #define CRC_SIZE_IN_BYTES 4
> #define MAX_VERSION_NUM 32
> #define INITIAL_CRC 0xffffffff
> #define ISO_LANGUAGE_CODE_LEN 3
>
> -static const u32 CRC_LUT[256] = {
> - /* from libdvbv5 */
> - 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
> - 0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
> - 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
> - 0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
> - 0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
> - 0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
> - 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
> - 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
> - 0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
> - 0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
> - 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
> - 0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
> - 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
> - 0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
> - 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
> - 0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
> - 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
> - 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
> - 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
> - 0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
> - 0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
> - 0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
> - 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
> - 0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
> - 0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
> - 0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
> - 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
> - 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
> - 0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
> - 0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
> - 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
> - 0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
> - 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
> - 0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
> - 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
> - 0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
> - 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
> - 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
> - 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
> - 0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
> - 0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
> - 0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
> - 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
> -};
> -
> -static u32 dvb_crc32(u32 crc, u8 *data, u32 len)
> -{
> - /* from libdvbv5 */
> - while (len--)
> - crc = (crc << 8) ^ CRC_LUT[((crc >> 24) ^ *data++) & 0xff];
> - return crc;
> -}
> -
> static void vidtv_psi_update_version_num(struct vidtv_psi_table_header *h)
> {
> h->version++;
> }
>
> @@ -173,11 +118,11 @@ static u32 vidtv_psi_ts_psi_write_into(struct
> psi_write_args *args)
>
> if (!args->crc && !args->is_crc)
> pr_warn_ratelimited("Missing CRC for chunk\n");
>
> if (args->crc)
> - *args->crc = dvb_crc32(*args->crc, args->from, args->len);
> + *args->crc = crc32_be(*args->crc, args->from, args->len);
>
> if (args->new_psi_section && !aligned) {
> pr_warn_ratelimited("Cannot write a new PSI section in a misaligned
> buffer\n");
>
> /* forcibly align and hope for the best */
>
> base-commit: 2d1373e4246da3b58e1df058374ed6b101804e07
> --
> 2.53.0
^ permalink raw reply [flat|nested] 2+ messages in thread
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