Re: spi/spi-pl022: Query on working of DMA mode
On 08/04/2011 03:46 PM, Linus Walleij wrote: > No maybe not, my test cases are for single messages, and on production > systems we mainly use IRQ-driven traffic. I need to have these > tests added I believe :-/ > > If you fix this up it will be much appreciated! Ya I am fixing this up. I have resolved this yesterday only, with GFP_NOWAIT. But it looks there are few more issues. Let me fix everything first and then will send patchset with updates. -- viresh -- BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA The must-attend event for mobile developers. Connect with experts. Get tools for creating Super Apps. See the latest technologies. Sessions, hands-on labs, demos & much more. Register early & save! http://p.sf.net/sfu/rim-blackberry-1 ___ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
Re: spi/spi-pl022: Query on working of DMA mode
On Thu, Aug 4, 2011 at 5:39 AM, viresh kumar wrote: >>> > Is DMA mode working in your case? >> Yes, magically :-/ > > But how? Don't you have any message with more than one transfer in it? No maybe not, my test cases are for single messages, and on production systems we mainly use IRQ-driven traffic. I need to have these tests added I believe :-/ If you fix this up it will be much appreciated! Thanks, Linus Walleij -- BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA The must-attend event for mobile developers. Connect with experts. Get tools for creating Super Apps. See the latest technologies. Sessions, hands-on labs, demos & much more. Register early & save! http://p.sf.net/sfu/rim-blackberry-1 ___ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
Re: spi/spi-pl022: Query on working of DMA mode
On 08/03/2011 08:28 PM, Linus Walleij wrote: >> > Here, allocation is requested with GFP_KERNEL flag, from a tasklet. >> > Which gives following crash logs: > What happens if you replace it with GFP_NOWAIT? > > That should work for everybody. > > Or you could remove the tasklet allover and replace it with a workqueue. > Ok. I will fix this and include in my patchset. >> > Is DMA mode working in your case? > Yes, magically :-/ But how? Don't you have any message with more than one transfer in it? -- viresh -- BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA The must-attend event for mobile developers. Connect with experts. Get tools for creating Super Apps. See the latest technologies. Sessions, hands-on labs, demos & much more. Register early & save! http://p.sf.net/sfu/rim-blackberry-1 ___ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
Re: spi/spi-pl022: Query on working of DMA mode
On Wed, Aug 3, 2011 at 1:32 PM, viresh kumar wrote: > tasklet_schedule(pump_transfers) > pump_transfers(unsigned long data) > configure_dma(pl022) > sg_alloc_table(&pl022->sgt_rx, pages, GFP_KERNEL); > > Here, allocation is requested with GFP_KERNEL flag, from a tasklet. > Which gives following crash logs: What happens if you replace it with GFP_NOWAIT? That should work for everybody. Or you could remove the tasklet allover and replace it with a workqueue. > Is DMA mode working in your case? Yes, magically :-/ Yours, Linus Walleij -- BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA The must-attend event for mobile developers. Connect with experts. Get tools for creating Super Apps. See the latest technologies. Sessions, hands-on labs, demos & much more. Register early & save! http://p.sf.net/sfu/rim-blackberry-1 ___ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
spi/spi-pl022: Query on working of DMA mode
Hi Linus, I am preparing few patches for spi-pl022 for "Allocating DMA channels as and when required". And i found something strange. When we have many transfers in a single message, following routines are called in specified order: tasklet_schedule(pump_transfers) pump_transfers(unsigned long data) configure_dma(pl022) sg_alloc_table(&pl022->sgt_rx, pages, GFP_KERNEL); Here, allocation is requested with GFP_KERNEL flag, from a tasklet. Which gives following crash logs: BUG: sleeping function called from invalid context at /data/csd_sw/spear/drives_os/vireshk/spear/kernel/linux-2.6/mm/slub.c:7 93 in_atomic(): 1, irqs_disabled(): 0, pid: 11, name: kworker/u:1 Backtrace: [<8003dabc>] (dump_backtrace+0x0/0x10c) from [<803aa4ec>] (dump_stack+0x18/0x1c) r6:0001 r5:00d0 r4:bf402200 r3:6113 [<803aa4d4>] (dump_stack+0x0/0x1c) from [<8004f330>] (__might_sleep+0xec/0x10c) [<8004f244>] (__might_sleep+0x0/0x10c) from [<800bbd2c>] (__kmalloc+0x74/0x110) [<800bbcb8>] (__kmalloc+0x0/0x110) from [<8019f69c>] (sg_kmalloc+0x2c/0x30) r8:80541b40 r7:0001 r6:0001 r5:0100 r4:bf47f1e8 r3: [<8019f670>] (sg_kmalloc+0x0/0x30) from [<8019f710>] (__sg_alloc_table+0x70/0x118) [<8019f6a0>] (__sg_alloc_table+0x0/0x118) from [<8019f7e0>] (sg_alloc_table+0x28/0x54) [<8019f7b8>] (sg_alloc_table+0x0/0x54) from [<802649a0>] (configure_dma+0x230/0x3fc) r5:bf47def8 r4:bf47f150 [<80264770>] (configure_dma+0x0/0x3fc) from [<8026509c>] (pump_transfers+0xcc/0x100) [<80264fd0>] (pump_transfers+0x0/0x100) from [<8005ecb0>] (tasklet_action+0xb0/0x160) r7:805203c4 r6:bf488000 r5:bf47f1a0 r4:bf47f19c [<8005ec00>] (tasklet_action+0x0/0x160) from [<8005f104>] (__do_softirq+0xa4/0x13c) [<8005f060>] (__do_softirq+0x0/0x13c) from [<8005f590>] (irq_exit+0x4c/0x54) [<8005f544>] (irq_exit+0x0/0x54) from [<80034094>] (asm_do_IRQ+0x94/0xd0) [<80034000>] (asm_do_IRQ+0x0/0xd0) from [<800396f4>] (__irq_svc+0x34/0xc0) Exception stack(0xbf489e90 to 0xbf489ed8) Now, i didn't get them earlier due to a mistake of mine. I have updated pl022_ssp_controller.enable_dma = 1, but didn't do pl022_config_chip.com_mode = DMA_TRANSFER So, finally DMA channels are allocated but never used, as both above must have been set. Today only I came to know of this mistake, and found it is actually not working, with above crash occurring. Is DMA mode working in your case? -- viresh -- BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA The must-attend event for mobile developers. Connect with experts. Get tools for creating Super Apps. See the latest technologies. Sessions, hands-on labs, demos & much more. Register early & save! http://p.sf.net/sfu/rim-blackberry-1 ___ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
