From: Oliver Hartkopp <socketcan@hartkopp.net>
To: gregkh@linuxfoundation.org, stable@vger.kernel.org, sashal@kernel.org
Cc: linux-can@vger.kernel.org, lukas.magel@posteo.net,
patches@lists.linux.dev, maxime.jayat@mobile-devices.fr,
mkl@pengutronix.de, michal.sojka@cvut.cz,
Oliver Hartkopp <socketcan@hartkopp.net>
Subject: [PATCH stable 5.10 04/10] can: isotp: set max PDU size to 64 kByte
Date: Tue, 31 Oct 2023 10:29:12 +0100 [thread overview]
Message-ID: <20231031092918.2668-5-socketcan@hartkopp.net> (raw)
In-Reply-To: <20231031092918.2668-1-socketcan@hartkopp.net>
commit 9c0c191d82a1de964ac953a1df8b5744ec670b07 upstream
The reason to extend the max PDU size from 4095 Byte (12 bit length value)
to a 32 bit value (up to 4 GByte) was to be able to flash 64 kByte
bootloaders with a single ISO-TP PDU. The max PDU size in the Linux kernel
implementation was set to 8200 Bytes to be able to test the length
information escape sequence.
It turns out that the demand for 64 kByte PDUs is real so the value for
MAX_MSG_LENGTH is set to 66000 to be able to potentially add some checksums
to the 65.536 Byte block.
Link: https://github.com/linux-can/can-utils/issues/347#issuecomment-1056142301
Link: https://lore.kernel.org/all/20220309120416.83514-3-socketcan@hartkopp.net
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
net/can/isotp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/can/isotp.c b/net/can/isotp.c
index ef72e5344789..fb179a333784 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -85,13 +85,13 @@ MODULE_ALIAS("can-proto-6");
(CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
/* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
* take full 32 bit values (4 Gbyte). We would need some good concept to handle
* this between user space and kernel space. For now increase the static buffer
- * to something about 8 kbyte to be able to test this new functionality.
+ * to something about 64 kbyte to be able to test this new functionality.
*/
-#define MAX_MSG_LENGTH 8200
+#define MAX_MSG_LENGTH 66000
/* N_PCI type values in bits 7-4 of N_PCI bytes */
#define N_PCI_SF 0x00 /* single frame */
#define N_PCI_FF 0x10 /* first frame */
#define N_PCI_CF 0x20 /* consecutive frame */
--
2.34.1
next prev parent reply other threads:[~2023-10-31 9:30 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-31 9:29 [PATCH stable 5.10 00/10] can: isotp: upgrade to latest 6.1 LTS code base Oliver Hartkopp
2023-10-31 9:29 ` [PATCH stable 5.10 01/10] can: isotp: change error format from decimal to symbolic error names Oliver Hartkopp
2023-10-31 9:29 ` [PATCH stable 5.10 02/10] can: isotp: add symbolic error message to isotp_module_init() Oliver Hartkopp
2023-10-31 9:29 ` [PATCH stable 5.10 03/10] can: isotp: Add error message if txqueuelen is too small Oliver Hartkopp
2023-10-31 9:29 ` Oliver Hartkopp [this message]
2023-10-31 9:29 ` [PATCH stable 5.10 05/10] can: isotp: isotp_bind(): return -EINVAL on incorrect CAN ID formatting Oliver Hartkopp
2023-10-31 9:29 ` [PATCH stable 5.10 06/10] can: isotp: check CAN address family in isotp_bind() Oliver Hartkopp
2023-10-31 9:29 ` [PATCH stable 5.10 07/10] can: isotp: handle wait_event_interruptible() return values Oliver Hartkopp
2023-10-31 9:29 ` [PATCH stable 5.10 08/10] can: isotp: add local echo tx processing and tx without FC Oliver Hartkopp
2023-10-31 9:29 ` [PATCH stable 5.10 09/10] can: isotp: isotp_bind(): do not validate unused address information Oliver Hartkopp
2023-10-31 9:29 ` [PATCH stable 5.10 10/10] can: isotp: isotp_sendmsg(): fix TX state detection and wait behavior Oliver Hartkopp
2023-11-06 11:23 ` [PATCH stable 5.10 00/10] can: isotp: upgrade to latest 6.1 LTS code base Greg KH
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