Re: [PATCH 27/30] ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop
On Mon, 8 Oct 2012 23:59:07 -0700 Jonathan Nieder wrote: > Feng Tang wrote: > > Jonathan Nieder wrote: > > >> What would go wrong if the threshold were just increased to 20 on all > >> models? > > > > Then some other platform will stop to work. > > https://bugzilla.kernel.org/show_bug.cgi?id=11892 > > > > The 26/30 and 27/30 patches are bound together to fix one bug. Some > > quote from description from the 26th patch: > > > > ACPI_EC_STORM_THRESHOLD was initially 20 when it's created, and > > was changed to 8 in 2.6.28 commit 06cf7d3c7 "ACPI: EC: lower interrupt storm > > threshold" to fix kernel bug 11892 by forcing the laptop in that bug to > > work in polling mode. > > > > Hope this answers your question. > > Thanks much. Yes, that clarifies. > > The magic numbers are not too thrilling. If the polling mode just > doesn't work on the Clevo M720, why isn't the appropriate storm > threshold 99 or infinity rather than 20? Do we know why the > polling mode doesn't work? I don't know why it doesn't work, if you check the https://bugzilla.kernel.org/show_bug.cgi?id=45151 you'll see the debugging model is test result --> patch --> 1-2 weeks + result --> patch --> 1-2 weeks + result ... over and over, which makes it difficult to root cause it but provide a workaround. And frankly speaking, I'm not sure if I can figure it out 100% even if I had that HW at hand. As per my understanding, EC is very tricky, as OS, ACPI FW, EC FW, BIOS will all access it without a global lock (in most cases), which makes it hard to work properly without race condition. Not mentioning its hardware may be broken. Thanks, Feng -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 27/30] ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop
Feng Tang wrote: > Jonathan Nieder wrote: >> What would go wrong if the threshold were just increased to 20 on all >> models? > > Then some other platform will stop to work. > https://bugzilla.kernel.org/show_bug.cgi?id=11892 > > The 26/30 and 27/30 patches are bound together to fix one bug. Some > quote from description from the 26th patch: > > ACPI_EC_STORM_THRESHOLD was initially 20 when it's created, and > was changed to 8 in 2.6.28 commit 06cf7d3c7 "ACPI: EC: lower interrupt storm > threshold" to fix kernel bug 11892 by forcing the laptop in that bug to > work in polling mode. > > Hope this answers your question. Thanks much. Yes, that clarifies. The magic numbers are not too thrilling. If the polling mode just doesn't work on the Clevo M720, why isn't the appropriate storm threshold 99 or infinity rather than 20? Do we know why the polling mode doesn't work? Jonathan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 27/30] ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop
Hi Jonathan, On Tue, 9 Oct 2012 14:16:33 +0800 Jonathan Nieder wrote: > Len Brown wrote: > > > By enlarging the GPE storm threshold back to 20, that laptop's > > EC works fine with interrupt mode instead of polling mode. > > What would go wrong if the threshold were just increased to 20 on all > models? Then some other platform will stop to work. https://bugzilla.kernel.org/show_bug.cgi?id=11892 The 26/30 and 27/30 patches are bound together to fix one bug. Some quote from description from the 26th patch: ACPI_EC_STORM_THRESHOLD was initially 20 when it's created, and was changed to 8 in 2.6.28 commit 06cf7d3c7 "ACPI: EC: lower interrupt storm threshold" to fix kernel bug 11892 by forcing the laptop in that bug to work in polling mode. Hope this answers your question. Thanks, Feng -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 27/30] ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop
Len Brown wrote: > By enlarging the GPE storm threshold back to 20, that laptop's > EC works fine with interrupt mode instead of polling mode. What would go wrong if the threshold were just increased to 20 on all models? Thanks, Jonathan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 27/30] ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop
Len Brown wrote: By enlarging the GPE storm threshold back to 20, that laptop's EC works fine with interrupt mode instead of polling mode. What would go wrong if the threshold were just increased to 20 on all models? Thanks, Jonathan -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 27/30] ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop
Hi Jonathan, On Tue, 9 Oct 2012 14:16:33 +0800 Jonathan Nieder jrnie...@gmail.com wrote: Len Brown wrote: By enlarging the GPE storm threshold back to 20, that laptop's EC works fine with interrupt mode instead of polling mode. What would go wrong if the threshold were just increased to 20 on all models? Then some other platform will stop to work. https://bugzilla.kernel.org/show_bug.cgi?id=11892 The 26/30 and 27/30 patches are bound together to fix one bug. Some quote from description from the 26th patch: ACPI_EC_STORM_THRESHOLD was initially 20 when it's created, and was changed to 8 in 2.6.28 commit 06cf7d3c7 ACPI: EC: lower interrupt storm threshold to fix kernel bug 11892 by forcing the laptop in that bug to work in polling mode. Hope this answers your question. Thanks, Feng -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 27/30] ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop
Feng Tang wrote: Jonathan Nieder jrnie...@gmail.com wrote: What would go wrong if the threshold were just increased to 20 on all models? Then some other platform will stop to work. https://bugzilla.kernel.org/show_bug.cgi?id=11892 The 26/30 and 27/30 patches are bound together to fix one bug. Some quote from description from the 26th patch: ACPI_EC_STORM_THRESHOLD was initially 20 when it's created, and was changed to 8 in 2.6.28 commit 06cf7d3c7 ACPI: EC: lower interrupt storm threshold to fix kernel bug 11892 by forcing the laptop in that bug to work in polling mode. Hope this answers your question. Thanks much. Yes, that clarifies. The magic numbers are not too thrilling. If the polling mode just doesn't work on the Clevo M720, why isn't the appropriate storm threshold 99 or infinity rather than 20? Do we know why the polling mode doesn't work? Jonathan -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 27/30] ACPI: EC: Add a quirk for CLEVO M720T/M730T laptop
On Mon, 8 Oct 2012 23:59:07 -0700 Jonathan Nieder jrnie...@gmail.com wrote: Feng Tang wrote: Jonathan Nieder jrnie...@gmail.com wrote: What would go wrong if the threshold were just increased to 20 on all models? Then some other platform will stop to work. https://bugzilla.kernel.org/show_bug.cgi?id=11892 The 26/30 and 27/30 patches are bound together to fix one bug. Some quote from description from the 26th patch: ACPI_EC_STORM_THRESHOLD was initially 20 when it's created, and was changed to 8 in 2.6.28 commit 06cf7d3c7 ACPI: EC: lower interrupt storm threshold to fix kernel bug 11892 by forcing the laptop in that bug to work in polling mode. Hope this answers your question. Thanks much. Yes, that clarifies. The magic numbers are not too thrilling. If the polling mode just doesn't work on the Clevo M720, why isn't the appropriate storm threshold 99 or infinity rather than 20? Do we know why the polling mode doesn't work? I don't know why it doesn't work, if you check the https://bugzilla.kernel.org/show_bug.cgi?id=45151 you'll see the debugging model is test result -- patch -- 1-2 weeks + result -- patch -- 1-2 weeks + result ... over and over, which makes it difficult to root cause it but provide a workaround. And frankly speaking, I'm not sure if I can figure it out 100% even if I had that HW at hand. As per my understanding, EC is very tricky, as OS, ACPI FW, EC FW, BIOS will all access it without a global lock (in most cases), which makes it hard to work properly without race condition. Not mentioning its hardware may be broken. Thanks, Feng -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
