From 2803527237c27bc18a0b9260e1dcbce9dfbbaae5 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Rafa=C5=82=20Mi=C5=82ecki?= Date: Tue, 16 Aug 2016 22:33:21 +0200 Subject: [PATCH] kernel: add BCM53573 flash fix sent upstream MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This fixes flash corruptions. It touches bcm47xxsflash driver shared between brcm47xx and bcm53xx so put it in generic. Signed-off-by: Rafał Miłecki --- ...h-use-uncached-MMIO-access-for-BCM53.patch | 57 +++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 target/linux/generic/patches-4.4/143-mtd-bcm47xxsflash-use-uncached-MMIO-access-for-BCM53.patch diff --git a/target/linux/generic/patches-4.4/143-mtd-bcm47xxsflash-use-uncached-MMIO-access-for-BCM53.patch b/target/linux/generic/patches-4.4/143-mtd-bcm47xxsflash-use-uncached-MMIO-access-for-BCM53.patch new file mode 100644 index 0000000000..98c62caf5f --- /dev/null +++ b/target/linux/generic/patches-4.4/143-mtd-bcm47xxsflash-use-uncached-MMIO-access-for-BCM53.patch @@ -0,0 +1,57 @@ +From 77fab8f7dc756ba65f37145c493cc04f17e36bea Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= +Date: Mon, 15 Aug 2016 14:13:09 +0200 +Subject: [PATCH] mtd: bcm47xxsflash: use uncached MMIO access for BCM53573 +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +BCM53573 is a new series of Broadcom's SoCs. It's based on ARM and uses +this old ChipCommon-based flash access. Early tests resulted in flash +corruptions that were tracked down to using cached MMIO for flash read +access. Switch to ioremap_nocache conditionally to support BCM53573 and +don't break performance on old MIPS devices. + +Signed-off-by: Rafał Miłecki +--- + drivers/mtd/devices/bcm47xxsflash.c | 24 +++++++++++++++++++----- + 1 file changed, 19 insertions(+), 5 deletions(-) + +--- a/drivers/mtd/devices/bcm47xxsflash.c ++++ b/drivers/mtd/devices/bcm47xxsflash.c +@@ -296,16 +296,30 @@ static int bcm47xxsflash_bcma_probe(stru + dev_err(dev, "can't request region for resource %pR\n", res); + return -EBUSY; + } +- b47s->window = ioremap_cache(res->start, resource_size(res)); +- if (!b47s->window) { +- dev_err(dev, "ioremap failed for resource %pR\n", res); +- return -ENOMEM; +- } + + b47s->bcma_cc = container_of(sflash, struct bcma_drv_cc, sflash); + b47s->cc_read = bcm47xxsflash_bcma_cc_read; + b47s->cc_write = bcm47xxsflash_bcma_cc_write; + ++ /* ++ * On old MIPS devices cache was magically invalidated when needed, ++ * allowing us to use cached access and gain some performance. Trying ++ * the same on ARM based BCM53573 results in flash corruptions, we need ++ * to use uncached access for it. ++ * ++ * It may be arch specific, but right now there is only 1 ARM SoC using ++ * this driver, so let's follow Broadcom's reference code and check ++ * ChipCommon revision. ++ */ ++ if (b47s->bcma_cc->core->id.rev == 54) ++ b47s->window = ioremap_nocache(res->start, resource_size(res)); ++ else ++ b47s->window = ioremap_cache(res->start, resource_size(res)); ++ if (!b47s->window) { ++ dev_err(dev, "ioremap failed for resource %pR\n", res); ++ return -ENOMEM; ++ } ++ + switch (b47s->bcma_cc->capabilities & BCMA_CC_CAP_FLASHT) { + case BCMA_CC_FLASHT_STSER: + b47s->type = BCM47XXSFLASH_TYPE_ST; -- 2.30.2