lwn.git/drivers/scsi/mac_scsi.c, branch v4.6-rc1

ncr5380: Fix soft lockups

2016-01-07T02:43:09+00:00

Because of the rudimentary design of the chip, it is necessary to poll the SCSI bus signals during PIO and this tends to hog the CPU. The driver will accept new commands while others execute, and this causes a soft lockup because the workqueue item will not terminate until the issue queue is emptied. When exercising dmx3191d using sequential IO from dd, the driver is sent 512 KiB WRITE commands and 128 KiB READs. For a PIO transfer, the rate is is only about 300 KiB/s, so these are long-running commands. And although PDMA may run at several MiB/s, interrupts are disabled for the duration of the transfer. Fix the unresponsiveness and soft lockup issues by calling cond_resched() after each command is completed and by limiting max_sectors for drivers that don't implement real DMA. Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen

ncr5380: Use standard list data structure

2016-01-07T02:43:07+00:00

The NCR5380 drivers have a home-spun linked list implementation for scsi_cmnd structs that uses cmd->host_scribble as a 'next' pointer. Adopt the standard list_head data structure and list operations instead. Remove the eh_abort_handler rather than convert it. Doing the conversion would only be churn because the existing EH handlers don't work and get replaced in a subsequent patch. Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen

ncr5380: Fix and cleanup scsi_host_template initializers

2016-01-07T02:43:03+00:00

Add missing .module initializer. Use distinct .proc_name values for the g_NCR5380 and g_NCR5380_mmio modules. Remove pointless CAN_QUEUE and CMD_PER_LUN override macros. Cleanup whitespace and code style. Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen

ncr5380: Cleanup #include directives

2016-01-07T02:43:02+00:00

Remove unused includes (stat.h, signal.h, proc_fs.h) and move includes needed by the core drivers into the common header (delay.h etc). Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen

ncr5380: Implement NCR5380_dma_xfer_len and remove LIMIT_TRANSFERSIZE macro

2016-01-07T02:42:56+00:00

Follow the example of the atari_NCR5380.c core driver and adopt the NCR5380_dma_xfer_len() hook. Implement NCR5380_dma_xfer_len() for dtc.c and g_NCR5380.c to take care of the limitations of these cards. Keep the default for drivers using PSEUDO_DMA. Eliminate the unused macro LIMIT_TRANSFERSIZE. Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen

ncr5380: Introduce unbound workqueue

2016-01-07T02:42:56+00:00

Allocate a work queue that will permit busy waiting and sleeping. This means NCR5380_init() can potentially fail, so add this error path. Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen

atari_NCR5380: Remove RESET_BOOT, CONFIG_ATARI_SCSI_TOSHIBA_DELAY and CONFIG_ATARI_SCSI_RESET_BOOT

2016-01-07T02:42:53+00:00

The atari_NCR5380.c core driver now takes care of bus reset upon driver initialization if required (same as NCR5380.c). Move the Toshiba CD-ROM support into the core driver, enabled with a host flag, so that all NCR5380 drivers can make use of it. Drop the RESET_BOOT macros and the ATARI_SCSI_RESET_BOOT and ATARI_SCSI_TOSHIBA_DELAY Kconfig symbols, which are now redundant. Remove the atari_scsi_reset_boot(), mac_scsi_reset_boot() and sun3_scsi_reset_boot() routines. None of this duplicated code is needed now that all drivers can use NCR5380_maybe_reset_bus(). This brings atari_scsi, mac_scsi and sun3_scsi into line with all of the other NCR5380 drivers. The bus reset may raise an interrupt. That would be new behaviour for atari_scsi only when CONFIG_ATARI_SCSI_RESET_BOOT=n. The ST DMA interrupt is not assigned to atari_scsi at this stage, so CONFIG_ATARI_SCSI_RESET_BOOT=y may well be problematic already. Regardless, do_reset() now raises and clears the interrupt within local_irq_save/restore which should avoid problems. Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen

ncr5380: Remove NCR5380_local_declare and NCR5380_setup macros

2016-01-07T02:42:52+00:00

The NCR5380_local_declare and NCR5380_setup macros exist to define and initialize a particular local variable, to provide the address of the chip registers needed for the driver's implementation of its NCR5380_read/write register access macros. In cumana_1 and macscsi, these macros generate pointless code like this, struct Scsi_Host *_instance; _instance = instance; In pas16, the use of NCR5380_read/write in pas16_hw_detect() requires that the io_port local variable has been defined and initialized, but the NCR5380_local_declare and NCR5380_setup macros can't be used for that purpose because the Scsi_Host struct has not yet been instantiated. Moreover, these macros were removed from atari_NCR5380.c long ago and now they constitute yet another discrepancy between the two core driver forks. Remove these "optimizations". Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Signed-off-by: Martin K. Petersen

ncr5380: Drop owner assignment from platform_drivers

2015-03-09T11:18:14+00:00

This platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang Signed-off-by: Finn Thain Signed-off-by: James Bottomley

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2014-12-12T18:08:06+00:00

Pull trivial tree update from Jiri Kosina: "Usual stuff: documentation updates, printk() fixes, etc" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits) intel_ips: fix a type in error message cpufreq: cpufreq-dt: Move newline to end of error message ps3rom: fix error return code treewide: fix typo in printk and Kconfig ARM: dts: bcm63138: change "interupts" to "interrupts" Replace mentions of "list_struct" to "list_head" kernel: trace: fix printk message scsi: mpt2sas: fix ioctl in comment zbud, zswap: change module author email clocksource: Fix 'clcoksource' typo in comment arm: fix wording of "Crotex" in CONFIG_ARCH_EXYNOS3 help gpio: msm-v1: make boolean argument more obvious usb: Fix typo in usb-serial-simple.c PCI: Fix comment typo 'COMFIG_PM_OPS' powerpc: Fix comment typo 'CONIFG_8xx' powerpc: Fix comment typos 'CONFiG_ALTIVEC' clk: st: Spelling s/stucture/structure/ isci: Spelling s/stucture/structure/ usb: gadget: zero: Spelling s/infrastucture/infrastructure/ treewide: Fix company name in module descriptions ...