[PATCH] clk: scpi: error when clock fails to register
From: jbrunet@baylibre.com (Jerome Brunet)
Date: 2017-06-29 08:50:31
Also in:
linux-clk, lkml
On Wed, 2017-06-28 at 18:07 +0100, Sudeep Holla wrote:
On 28/06/17 17:46, Jerome Brunet wrote:quoted
On Wed, 2017-06-28 at 16:52 +0100, Sudeep Holla wrote:[..]quoted
quoted
Thanks for this stack. I just worked out the same path now. I did come up with the patch as below. That should work if my understanding is correct.I tried.Thanks.quoted
It does not work unfortunately. Still crashes but somewhere else: [????2.301482] [<ffff00000849e67c>] scpi_of_clk_src_get+0x14/0x58 [????2.307261] [<ffff000008495f40>] __of_clk_get_by_name+0x100/0x118 [????2.313297] [<ffff000008495fac>] clk_get+0x2c/0x78 [????2.318044] [<ffff00000856f4d0>] dev_pm_opp_get_opp_table+0xb0/0x118 [????2.324338] [<ffff00000856fd00>] dev_pm_opp_add+0x20/0x68 [????2.329687] [<ffff0000087a04f8>] scpi_init_opp_table+0xa8/0x188 [????2.335550] [<ffff00000879fb20>] _get_cluster_clk_and_freq_table+0x80/0x180 [????2.342450] [<ffff0000087a0010>] bL_cpufreq_init+0x3f0/0x480 [????2.348056] [<ffff00000879e4a0>] cpufreq_online+0xc0/0x658 [????2.353490] [<ffff00000879eac8>] cpufreq_add_dev+0x78/0x88 [????2.358924] [<ffff00000855b684>] subsys_interface_register+0x84/0xc8 [????2.365220] [<ffff00000879d8f8>] cpufreq_register_driver+0x138/0x1b8 [????2.371516] [<ffff0000087a0114>] bL_cpufreq_register+0x74/0x120 [????2.377381] [<ffff0000087a0600>] scpi_cpufreq_probe+0x28/0x38 [????2.383076] [<ffff00000855efb0>] platform_drv_probe+0x50/0xb8 [????2.388766] [<ffff00000855d144>] driver_probe_device+0x21c/0x2d8Looks like a different route and I know why. I have added an extra check now which should work if I have not missed anything more.quoted
I have not looked at ALL the clock providers, but I have seen a few and I don't remember seeing any which fails, at some point, to register a clocks and still register successfully.?No problem, as I said I am fine with the patch you sent as a fix for now but just curious to know what are the issues to be fixed to continue supporting that feature. Please bear with me.
I am :) and I understand what you are trying to do, having a degraded clock provider is better than nothing according to you, correct? I'm wondering whether this is correct or not, that why I'm challenging this a bit. If you failed to register an scpi clock it is probably because the communication with the FW is not working, or at least 'not that good', right ? If for some reason, you manage to register some other clocks from the same FW, how confident can you be that communication will be ok for them ? that the settings you request will be applied correctly ? Is it possible that you may be causing more harm/damage playing with a broken HW ?
quoted
It seems strange to continue with a broken controller.I would have agreed if it was single driver or h/w controlled by Linux. Since it's in the firmware, we should allow the working clocks/opps to work though few are broken. It's not good if we had to disable everything if some piece of firmware is not yet ready or broken. But again, we can get it working later, for now, I am fine with you patch.
I tried your last version, and it does not Oops, at least not for me. The end result still looks odd to me: [????1.115219] scpi_clocks scpi:clocks: failed to register clock 'vcpu' [????1.159490] cpu cpu0: _get_cluster_clk_and_freq_table: Failed to get clk for cpu: 0, cluster: 0 [????1.162986] cpu cpu0: _get_cluster_clk_and_freq_table: Failed to get data for cluster: 0 [????1.170945] cpu cpu1: _get_cluster_clk_and_freq_table: Failed to get clk for cpu: 1, cluster: 0 [????1.179634] cpu cpu1: _get_cluster_clk_and_freq_table: Failed to get data for cluster: 0 [????1.187654] cpu cpu2: _get_cluster_clk_and_freq_table: Failed to get clk for cpu: 2, cluster: 0 [????1.196284] cpu cpu2: _get_cluster_clk_and_freq_table: Failed to get data for cluster: 0 [????1.204375] cpu cpu3: _get_cluster_clk_and_freq_table: Failed to get clk for cpu: 3, cluster: 0 [????1.212911] cpu cpu3: _get_cluster_clk_and_freq_table: Failed to get data for cluster: 0 [????1.220612] arm_big_little: bL_cpufreq_register: Registered platform driver: scpi So now, I have an scpi clock provider which registers successfully but fails to register its only clock. As a consequence, I also have a cpufreq driver which manages to register but has no clock cpu clock to drive ...
quoted hunk ↗ jump to hunk
Regards, Sudeep ---diff --git i/drivers/clk/clk-scpi.c w/drivers/clk/clk-scpi.c index 96d37175d0ad..a0b9b4c84be3 100644 --- i/drivers/clk/clk-scpi.c +++ w/drivers/clk/clk-scpi.c@@ -192,7 +192,7 @@ scpi_of_clk_src_get(struct of_phandle_args *clkspec,void *data) ????????for (count = 0; count < clk_data->clk_num; count++) { ????????????????sclk = clk_data->clk[count]; -???????????????if (idx == sclk->id) +???????????????if (sclk && idx == sclk->id) ????????????????????????return &sclk->hw; ????????}@@ -245,11 +245,14 @@ static int scpi_clk_add(struct device *dev, structdevice_node *np, ????????????????sclk->id = val; ????????????????err = scpi_clk_ops_init(dev, match, sclk, name); -???????????????if (err) +???????????????if (err) { ????????????????????????dev_err(dev, "failed to register clock '%s'\n", name); -???????????????else +???????????????????????clk_data->clk[idx] = NULL; +???????????????????????devm_kfree(dev, sclk); +???????????????} else { ????????????????????????dev_dbg(dev, "Registered clock '%s'\n", name); -???????????????clk_data->clk[idx] = sclk; +???????????????????????clk_data->clk[idx] = sclk; +???????????????} ????????} ????????return of_clk_add_hw_provider(np, scpi_of_clk_src_get, clk_data); -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo at vger.kernel.org More majordomo info at??http://vger.kernel.org/majordomo-info.html