d5fcc710a1
This patch series is a new version of the previous patch posted: [PATCH v2] spi: spi-geni-qcom: Speculative fix of "nobody cared" about interrupt https://lore.kernel.org/r/20200317133653.v2.1.I752ebdcfd5e8bf0de06d66e767b8974932b3620e@changeid At this point I've done enough tracing to know that there was a real race in the old code (not just weakly ordered memory problems) and that should be fixed with the locking patches. While looking at this driver, I also noticed we weren't properly noting error interrupts and also weren't actually using our FIFO effectively, so I fixed those. The last patch in the series addresses review feedback about dislike for the "cur_mcmd" state variable. It also could possibly make "abort" work ever-so-slightly more reliably. Changes in v4: - Drop 'controller' in comment. - Use Stephen's diagram to explain the race better. Changes in v3: - ("spi: spi-geni-qcom: No need for irqsave variant...") new for v3 - Split out some lock cleanup to previous patch. - Don't need to read IRQ status register inside spinlock. - Don't check for state CMD_NONE; later patch is removing state var. - Don't hold the lock for all of setup_fifo_xfer(). - Comment about why it's safe to Ack interrupts at the end. - Subject/desc changed since race is definitely there. - ("spi: spi-geni-qcom: Check for error IRQs") new in v3. - ("spi: spi-geni-qcom: Actually use our FIFO") new in v3. - ("spi: spi-geni-qcom: Don't keep a local state variable") new in v3. Changes in v2: - Detect true spurious interrupt. - Still return IRQ_NONE for state machine mismatch, but print warn. Douglas Anderson (5): spi: spi-geni-qcom: No need for irqsave variant of spinlock calls spi: spi-geni-qcom: Mo' betta locking spi: spi-geni-qcom: Check for error IRQs spi: spi-geni-qcom: Actually use our FIFO spi: spi-geni-qcom: Don't keep a local state variable drivers/spi/spi-geni-qcom.c | 120 ++++++++++++++++++++++++------------ 1 file changed, 81 insertions(+), 39 deletions(-) -- 2.27.0.290.gba653c62da-goog
Linux kernel
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