kernel.git/drivers/dma/at_xdmac.c, branch linux-4.0.y

dmaengine: at_xdmac: lock fixes

2015-06-23T00:03:27Z

commit 4c374fc7ce944024936a6d9804daec85207d9384 upstream. Using _bh variant for spin locks causes this kind of warning: Starting logging: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 3 at /ssd_drive/linux/kernel/softirq.c:151 __local_bh_enable_ip+0xe8/0xf4() Modules linked in: CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 4.1.0-rc2+ #94 Hardware name: Atmel SAMA5 [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (warn_slowpath_common+0x80/0xac) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24) [] (warn_slowpath_null) from [] (__local_bh_enable_ip+0xe8/0xf4) [] (__local_bh_enable_ip) from [] (at_xdmac_device_terminate_all+0xf4/0x100) [] (at_xdmac_device_terminate_all) from [] (atmel_complete_tx_dma+0x34/0xf4) [] (atmel_complete_tx_dma) from [] (at_xdmac_tasklet+0x14c/0x1ac) [] (at_xdmac_tasklet) from [] (tasklet_action+0x68/0xb4) [] (tasklet_action) from [] (__do_softirq+0xfc/0x238) [] (__do_softirq) from [] (run_ksoftirqd+0x28/0x34) [] (run_ksoftirqd) from [] (smpboot_thread_fn+0x138/0x18c) [] (smpboot_thread_fn) from [] (kthread+0xdc/0xf0) [] (kthread) from [] (ret_from_fork+0x14/0x34) ---[ end trace b57b14a99c1d8812 ]--- It comes from the fact that devices can called some code from the DMA controller with irq disabled. _bh variant is not intended to be used in this case since it can enable irqs. Switch to irqsave/irqrestore variant to avoid this situation. Signed-off-by: Ludovic Desroches Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: at_xdmac: rework slave configuration part

2015-06-23T00:03:27Z

commit 765c37d876698268eea8b820081ac8fc9d0fc8bc upstream. Rework slave configuration part in order to more report wrong errors about the configuration. Only maxburst and addr width values are checked when doing the slave configuration. The validity of the channel configuration is done at prepare time. Signed-off-by: Ludovic Desroches Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: at_xdmac: fix for chan conf simplification

2015-03-05T08:59:57Z

When simplificating the channel configuration, the cyclic case has been forgotten. It leads to use bad configuration causing many bugs. Signed-off-by: Ludovic Desroches Acked-by: Nicolas Ferre Signed-off-by: Vinod Koul

dmaengine: at_xdmac: allow muliple dwidths when doing slave transfers

2015-02-05T07:12:29Z

When using FIFO, we need to support differents data width in a single transfer. For example, serial device which usually uses 1-byte data width will use 4-bytes data width when using the FIFO. If the transfer size is not aligned on 4-bytes then the end of the transfer will be performed with 1-byte data-width. For that reason, at_xdmac_prep_slave_sg() now builds linked list descriptors using view 2 instead of view 1 so each of them can update the DWIDTH field into the Channel Configuration Register. Signed-off-by: Cyrille Pitchen Signed-off-by: Ludovic Desroches Signed-off-by: Vinod Koul

dmaengine: at_xdmac: simplify channel configuration stuff

2015-02-05T07:12:29Z

This patch simplifies the channel configuration register management. Relying on a "software snapshot" of the configuration is not safe and too complex. Multiple dwidths will be introduced for slave transfers. In this case, it becomes quite difficult to have an accurate snapshot of the channel configuration register in the way it is done. Using the channel configuration available in the lli descriptor simplifies this stuff. Signed-off-by: Ludovic Desroches Signed-off-by: Vinod Koul

dmaengine: at_xdmac: introduce save_cc field

2015-02-05T07:12:28Z

When suspending the device, read the channel configuration directly from the register instead of relying on a software snapshot, it will be safer. Signed-off-by: Ludovic Desroches Signed-off-by: Vinod Koul

dmaengine: at_xdmac: wait for in-progress transaction to complete after pausing a channel

2015-02-05T07:12:28Z

Signed-off-by: Cyrille Pitchen Signed-off-by: Ludovic Desroches Signed-off-by: Vinod Koul

Merge branch 'topic/slave_caps_device_control_fix_rebased' into for-linus

2015-02-03T00:55:35Z

dmaengine: drop owner assignment from platform_drivers

2015-01-13T17:35:04Z

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: Vinod Koul

dmaengine: at_xdmac: Declare slave capabilities for the generic code

2014-12-22T07:03:23Z

Now that the generic slave caps code can make use of the device assigned capabilities, instead of relying on a callback to be implemented. Make use of this code. Signed-off-by: Ludovic Desroches Signed-off-by: Maxime Ripard Signed-off-by: Vinod Koul