diff options
Diffstat (limited to 'target/linux/generic/patches-4.4/042-0003-mtd-bcm47xxsflash-use-uncached-MMIO-access-for-BCM53.patch')
| -rw-r--r-- | target/linux/generic/patches-4.4/042-0003-mtd-bcm47xxsflash-use-uncached-MMIO-access-for-BCM53.patch | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.4/042-0003-mtd-bcm47xxsflash-use-uncached-MMIO-access-for-BCM53.patch b/target/linux/generic/patches-4.4/042-0003-mtd-bcm47xxsflash-use-uncached-MMIO-access-for-BCM53.patch new file mode 100644 index 0000000000..c2f2d21d03 --- /dev/null +++ b/target/linux/generic/patches-4.4/042-0003-mtd-bcm47xxsflash-use-uncached-MMIO-access-for-BCM53.patch @@ -0,0 +1,59 @@ +From 64ad46379fcf14f437553f654d1adcd3d0e0d7f9 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl> +Date: Mon, 15 Aug 2016 14:21:28 +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 <rafal@milecki.pl> +Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> +Signed-off-by: Brian Norris <computersforpeace@gmail.com> +--- + 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; |