From c3a1c8e7a6b36b2e46f671768c073f56f0c235e2 Mon Sep 17 00:00:00 2001 From: AceLan Kao Date: Thu, 26 Sep 2019 16:32:49 +0800 Subject: [PATCH] mfd: intel-lpss: add quirk for Dell XPS 13 7390 2-in-1 The memory region intel-lpss-pci uses has been declared as write-combining [ 0.001728] 5 base 4000000000 mask 6000000000 write-combining This leads to the system hangs up during booting up. Tuowen Zhao(ztuowen@gmail.com) provides a diff patch for intel-lpss driver to claim to use un-catchable memory while calling __devm_ioremap(), and it works well. To avoid the potential impact on other machines, I add a quirk to list the machines which has the write-combining area in MTRR which overlaps with the address that intel-lpss uses, only the machines in the list pass the DEVM_IOREMAP_UC to __devm_ioremap(). Link: https://bugzilla.kernel.org/show_bug.cgi?id=203485 Signed-off-by: AceLan Kao --- drivers/mfd/intel-lpss.c | 20 ++++++++++++++++++-- include/linux/io.h | 2 ++ lib/devres.c | 20 ++++++++++++++++++++ 3 files changed, 40 insertions(+), 2 deletions(-) diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c index 277f48f1cc1c..5223aba7ba1d 100644 --- a/drivers/mfd/intel-lpss.c +++ b/drivers/mfd/intel-lpss.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -128,6 +129,17 @@ static const struct mfd_cell intel_lpss_spi_cell = { static DEFINE_IDA(intel_lpss_devid_ida); static struct dentry *intel_lpss_debugfs; +static const struct dmi_system_id mtrr_large_wc_region[] = { + { + .ident = "Dell Computer Corporation", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "XPS 13 7390 2-in-1"), + }, + }, + { } +}; + static int intel_lpss_request_dma_module(const char *name) { static bool intel_lpss_dma_requested; @@ -395,8 +407,12 @@ int intel_lpss_probe(struct device *dev, if (!lpss) return -ENOMEM; - lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET, - LPSS_PRIV_SIZE); + if (dmi_check_system(mtrr_large_wc_region)) + lpss->priv = devm_ioremap_uc(dev, info->mem->start + LPSS_PRIV_OFFSET, + LPSS_PRIV_SIZE); + else + lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET, + LPSS_PRIV_SIZE); if (!lpss->priv) return -ENOMEM; diff --git a/include/linux/io.h b/include/linux/io.h index accac822336a..a59834bc0a11 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -64,6 +64,8 @@ static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr) void __iomem *devm_ioremap(struct device *dev, resource_size_t offset, resource_size_t size); +void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset, + resource_size_t size); void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset, resource_size_t size); void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, diff --git a/lib/devres.c b/lib/devres.c index 6a0e9bd6524a..ca4a18f71798 100644 --- a/lib/devres.c +++ b/lib/devres.c @@ -9,6 +9,7 @@ enum devm_ioremap_type { DEVM_IOREMAP = 0, DEVM_IOREMAP_NC, + DEVM_IOREMAP_UC, DEVM_IOREMAP_WC, }; @@ -39,6 +40,9 @@ static void __iomem *__devm_ioremap(struct device *dev, resource_size_t offset, case DEVM_IOREMAP_NC: addr = ioremap_nocache(offset, size); break; + case DEVM_IOREMAP_UC: + addr = ioremap_uc(offset, size); + break; case DEVM_IOREMAP_WC: addr = ioremap_wc(offset, size); break; @@ -68,6 +72,22 @@ void __iomem *devm_ioremap(struct device *dev, resource_size_t offset, } EXPORT_SYMBOL(devm_ioremap); +/** + * devm_ioremap_uc - Managed ioremap_uc() + * @dev: Generic device to remap IO address for + * @offset: Resource address to map + * @size: Size of map + * + * Managed ioremap_uc(). Map is automatically unmapped on driver detach. + */ +void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset, + resource_size_t size) +{ + return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_UC); +} +EXPORT_SYMBOL(devm_ioremap_uc); + + /** * devm_ioremap_nocache - Managed ioremap_nocache() * @dev: Generic device to remap IO address for -- 2.17.1