On Tue, May 14, 2019 at 01:14:08PM +0300, Serge Semin wrote: > I started using this driver two years ago in kernek 4.4 and then in kernel > 4.9. It didn't go well from the very beginning due to my platform > peculiarities: DW SPI core with hardware CS and relatively slow MIPS-based > SoC. This patchset is intended to fix some of the problems I found out > during the max310x driver utilization with max14830 device. > > First of all it was discovered, that workqueue API isn't optimally used. > Work context isn't re-entrant by design, so the mutex used to guard the > TX-method is redundant. schedule_work() method is also created in a way > the work item is scheduled only if it isn't pending. Patch 1 concerns all > these fixes. Seeing the similar container_of(uart_port) is used three > times in the driver, the patch 2 introduces a macro to_max310x_port() to > get a pointer to corresponding struct max310x_one. This is the code > simplification and is going to be used in the following patches. > > It was found out, that batch read and write methods used buffers allocated > on the kernel stack. Since they might be utilized by SPI controllers for > DMA it might be unsafe on some platforms. Patch 3 provides a dedicated > kmalloced buffers for this. > > The baud-rate calculator function didn't work correct for all the possible > baud-rates requested within a pre-defined input reference frequency. > Instead an algo fully compliant with datasheet divisor formulae is > implemented in patch 4. > > Patches 5 and 6 are created to fix some rs485 issues. Particularly the > rs485 mode is configured on the port startup if it's enabled. And seeing > the mode2 register provides a way to enable/disable the echo-suppression > in RS485 mode, it is used to implement the SER_RS485_RX_DURING_TX flag > support. > > Finally it was discovered that in case if inbound hardware FIFO > experienced overflow, a lot of '\0' characters inserted into the > flip-buffer as a character of the RX-FIFO overrun. It isn't quite correct > since the overflow happened only after the last character had been > received. Patch 7 is dedicated to push only a single RX-FIFO overrun > character in this case. > > Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx> Nice cleanups, all now applied, thanks! greg k-h
