On 11.06.2025 17:37:29, Geert Uytterhoeven wrote: > Hi all, > > This patch series adds CAN-FD Transceiver Delay Compensation support to > the R-Car CAN-FD driver, after the customary cleanups and refactorings. > There's no reference to footnote [1], as it refers to the v1, I'll add it here. > Changes compared to v1: Changes compared to v1 [1]: > - Dropped patch "can: rcar_canfd: Use ndev parameter in > rcar_canfd_set_bittiming()", > - New patch "[PATCH v2 02/10] can: rcar_canfd: Remove bittiming debug > prints", > - New patch "[PATCH v2 07/10] can: rcar_canfd: Rename > rcar_canfd_setrnc() to rcar_canfd_set_rnc()", > - Add Reviewed-by, > - Replace function-like RCANFD_F_*() macros by rcar_canfd_f_*() > inline functions, > - Replace function-like macro RCANFD_FDSTS_TDCR() by bitmask > RCANFD_FDSTS_TDCR and helper function rcar_canfd_get_tdcr(), > - Replace function-like macro RCANFD_FDSTS_TDCVF() by two bit > definitions, > - Drop debug print of tdc mode and tdco value. > > This has been tested on R-Car V4H (White Hawk), V4M (Gray Hawk Single), > and E3 (Ebisu-4D[2]), using various data bit rates. Without proper TDC > configuration, transmitting at 8 Mbps makes the CAN-FD controller enter > BUS-OFF state. The TDCV value as measured by the CAN-FD controller is 4 > on all boards tested (base clock 40 MHz, i.e. 25 ns period), and ca. 90 > ns as measured by a logic analyzer on Gray Hawk Single. > > Note that the BSP (predating upstream TDC support), uses a much simpler > method: for transfer rates >= 5 Mbps on R-Car Gen4, it enables TDC with > a hardcoded (hardware) TDCO value of 2 (i.e. actual 3), which matches > the behavior of this series at 8 Mbps. > > Thanks for your comments! > > [1] "[PATCH 0/9] can: rcar_canfd: Add support for Transceiver Delay Compensation" > https://lore.kernel.org/cover.1748863848.git.geert+renesas@xxxxxxxxx regards, Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung Nürnberg | Phone: +49-5121-206917-129 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |
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