| Message ID | 1609219662-27057-1-git-send-email-yilun.xu@intel.com |
|---|---|
| Headers | show |
| Series | fix the issue when xfer by spi-altera | expand |
On Tue, 29 Dec 2020 13:27:40 +0800, Xu Yilun wrote: > When doing spi xfer by spi-altera, divide by 0 exception happens in > spi_transfer_wait(), This is because the xfer->speed_hz is always > clamped to 0 by spi->controller->max_speed_hz, the feature is > introduced in: > > commit 9326e4f1e5dd ("spi: Limit the spi device max speed to controller's max speed") > > [...] Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next Thanks! [1/2] spi: altera: fix return value for altera_spi_txrx() commit: ede090f5a438e97d0586f64067bbb956e30a2a31 All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
When doing spi xfer by spi-altera, divide by 0 exception happens in spi_transfer_wait(), This is because the xfer->speed_hz is always clamped to 0 by spi->controller->max_speed_hz, the feature is introduced in: commit 9326e4f1e5dd ("spi: Limit the spi device max speed to controller's max speed") The spi-altera doesn't have hardware indication for controller's max_speed_hz, so its value is uninitialized as 0. Patch #1 fixes the issue of spi_altera driver. When doing polling mode xfer, its transfer_one() callback should return 1, to indicate the xfer is finished. It should return 0 for irq mode xfer. With this patch the polling mode xfer is OK as it needs no spi_transfer_wait() anymore. But the irq mode xfer is still broken. So Patch #2 assumes 1khz xfer speed if the xfer->speed_hz is not assigned. I try to avoid the divide by 0 issue and ensures a reasonable tolerant waiting time in a generic way. Xu Yilun (2): spi: altera: fix return value for altera_spi_txrx() spi: fix the divide by 0 error when calculating xfer waiting time drivers/spi/spi-altera.c | 26 ++++++++++++++------------ drivers/spi/spi.c | 4 +++- 2 files changed, 17 insertions(+), 13 deletions(-)