mirror of
https://github.com/torvalds/linux
synced 2024-10-12 06:16:26 +00:00
5a6a0445d1
There is nothing that says that number of TX queues == number of RX
queues. E.g. the ARTPEC-6 SoC has 2 TX queues and 1 RX queue.
This code is obviously wrong:
for (chan = 0; chan < tx_channel_count; chan++) {
struct stmmac_rx_queue *rx_q = &priv->rx_queue[chan];
priv->rx_queue has size MTL_MAX_RX_QUEUES, so this will send an
uninitialized napi_struct to __napi_schedule(), causing us to
crash in net_rx_action(), because napi_struct->poll is zero.
[12846.759880] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[12846.768014] pgd = (ptrval)
[12846.770742] [00000000] *pgd=39ec7831, *pte=00000000, *ppte=00000000
[12846.777023] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
[12846.782942] Modules linked in:
[12846.785998] CPU: 0 PID: 161 Comm: dropbear Not tainted 4.15.0-rc2-00285-gf5fb5f2f39a7 #36
[12846.794177] Hardware name: Axis ARTPEC-6 Platform
[12846.798879] task: (ptrval) task.stack: (ptrval)
[12846.803407] PC is at 0x0
[12846.805942] LR is at net_rx_action+0x274/0x43c
[12846.810383] pc : [<00000000>] lr : [<80bff064>] psr: 200e0113
[12846.816648] sp : b90d9ae8 ip : b90d9ae8 fp : b90d9b44
[12846.821871] r10: 00000008 r9 : 0013250e r8 : 00000100
[12846.827094] r7 : 0000012c r6 : 00000000 r5 : 00000001 r4 : bac84900
[12846.833619] r3 : 00000000 r2 : b90d9b08 r1 : 00000000 r0 : bac84900
Since each DMA channel can be used for rx and tx simultaneously,
the current code should probably be rewritten so that napi_struct is
embedded in a new struct stmmac_channel.
That way, stmmac_poll() can call stmmac_tx_clean() on just the tx queue
where we got the IRQ, instead of looping through all tx queues.
This is also how the xgbe driver does it (another driver for this IP).
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.