Hello Marc, On Thursday 28 of April 2022 09:22:39 Marc Kleine-Budde wrote: > > Jiapeng Chong (2): > > can: ctucanfd: Remove unnecessary print function dev_err() > > can: ctucanfd: Remove unused including <linux/version.h> > > I had these already applied. > > > Pavel Pisa (2): > > can: ctucanfd: remove PCI module debug parameters and core debug > > statements. > > docs: networking: device drivers: can: add ctucanfd and its author > > e-mail update > > Split into separate patches and applied. Excuse me for late reply and thanks much for split to preferred form. Matej Vasilevski has tested updated linux-can-next testing on Xilinx Zynq 7000 based MZ_APO board and used it with his patches to do proceed next round of testing of Jan Charvat's NuttX TWAI (CAN) driver on ESP32C3. We plan that CTU CAN FD timestamping will be send for RFC/discussion soon. I would like to thank to Andrew Dennison who implemented, tested and shares integration with LiteX and RISC-V https://github.com/litex-hub/linux-on-litex-vexriscv He uses development version of the CTU CAN FD IP core with configurable number of Tx buffers (2 to 8) for which will be required automatic setup logic in the driver. I need to discuss with Ondrej Ille actual state and his plans. But basically ntxbufs in the ctucan_probe_common() has to be assigned from TXTB_INFO TXT_BUFFER_COUNT field. For older core version the TXT_BUFFER_COUNT field bits should be equal to zero so when value is zero, the original version with fixed 4 buffers will be recognized. When value is configurable then for (uncommon) number of buffers which is not power of two, there will be likely a problem with way how buffers queue is implemented txtb_id = priv->txb_head % priv->ntxbufs; ... priv->txb_head++; ... priv->txb_tail++; When I have provided example for this type of queue many years ago I have probably shown example with power of 2 masking, but modulo by arbitrary number does not work with sequence overflow. Which means to add there two "if"s unfortunately if (++priv->txb_tail == 2 * priv->ntxbufs) priv->txb_tail = 0; We need 2 * priv->ntxbufs range to distinguish empty and full queue... But modulo is not nice either so I probably come with some other solution in a longer term. In the long term, I want to implement virtual queues to allow multiqueue to use dynamic Tx priority of up to 8 the buffers... Best wishes, Pavel Pisa phone: +420 603531357 e-mail: pisa@xxxxxxxxxxxxxxxx Department of Control Engineering FEE CVUT Karlovo namesti 13, 121 35, Prague 2 university: http://control.fel.cvut.cz/ personal: http://cmp.felk.cvut.cz/~pisa projects: https://www.openhub.net/accounts/ppisa CAN related:http://canbus.pages.fel.cvut.cz/ Open Technologies Research Education and Exchange Services https://gitlab.fel.cvut.cz/otrees/org/-/wikis/home
