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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, "Lukas Wunner" <lukas@wunner.de>,
	"Mathias Duckeck" <m.duckeck@kunbus.de>,
	"Frank Pavlic" <f.pavlic@kunbus.de>,
	"Martin Sperl" <kernel@martin.sperl.org>,
	"Noralf Trønnes" <noralf@tronnes.org>,
	"Mark Brown" <broonie@kernel.org>
Subject: [PATCH 4.4 48/88] spi: bcm2835: Avoid finishing transfer prematurely in IRQ mode
Date: Fri, 11 Jan 2019 15:08:17 +0100
Message-ID: <20190111131053.213760317@linuxfoundation.org> (raw)
In-Reply-To: <20190111131045.137499039@linuxfoundation.org>

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Lukas Wunner <lukas@wunner.de>

commit 56c1723426d3cfd4723bfbfce531d7b38bae6266 upstream.

The IRQ handler bcm2835_spi_interrupt() first reads as much as possible
from the RX FIFO, then writes as much as possible to the TX FIFO.
Afterwards it decides whether the transfer is finished by checking if
the TX FIFO is empty.

If very few bytes were written to the TX FIFO, they may already have
been transmitted by the time the FIFO's emptiness is checked.  As a
result, the transfer will be declared finished and the chip will be
reset without reading the corresponding received bytes from the RX FIFO.

The odds of this happening increase with a high clock frequency (such
that the TX FIFO drains quickly) and either passing "threadirqs" on the
command line or enabling CONFIG_PREEMPT_RT_BASE (such that the IRQ
handler may be preempted between filling the TX FIFO and checking its
emptiness).

Fix by instead checking whether rx_len has reached zero, which means
that the transfer has been received in full.  This is also more
efficient as it avoids one bus read access per interrupt.  Note that
bcm2835_spi_transfer_one_poll() likewise uses rx_len to determine
whether the transfer has finished.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Fixes: e34ff011c70e ("spi: bcm2835: move to the transfer_one driver model")
Cc: stable@vger.kernel.org # v4.1+
Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Frank Pavlic <f.pavlic@kunbus.de>
Cc: Martin Sperl <kernel@martin.sperl.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/spi/spi-bcm2835.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -155,8 +155,7 @@ static irqreturn_t bcm2835_spi_interrupt
 	/* Write as many bytes as possible to FIFO */
 	bcm2835_wr_fifo(bs);
 
-	/* based on flags decide if we can finish the transfer */
-	if (bcm2835_rd(bs, BCM2835_SPI_CS) & BCM2835_SPI_CS_DONE) {
+	if (!bs->rx_len) {
 		/* Transfer complete - reset SPI HW */
 		bcm2835_spi_reset_hw(master);
 		/* wake up the framework */



  parent reply index

Thread overview: 102+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-11 14:07 [PATCH 4.4 00/88] 4.4.170-stable review Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 01/88] USB: hso: Fix OOB memory access in hso_probe/hso_get_config_data Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 02/88] xhci: Dont prevent USB2 bus suspend in state check intended for USB3 only Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 03/88] USB: serial: option: add GosunCn ZTE WeLink ME3630 Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 04/88] USB: serial: option: add HP lt4132 Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 05/88] USB: serial: option: add Simcom SIM7500/SIM7600 (MBIM mode) Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 06/88] USB: serial: option: add Fibocom NL668 series Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 07/88] USB: serial: option: add Telit LN940 series Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 08/88] mmc: core: Reset HPI enabled state during re-init and in case of errors Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 09/88] mmc: omap_hsmmc: fix DMA API warning Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 10/88] gpio: max7301: fix driver for use with CONFIG_VMAP_STACK Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 11/88] Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 12/88] x86/mtrr: Dont copy uninitialized gentry fields back to userspace Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 13/88] drm/ioctl: Fix Spectre v1 vulnerabilities Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 14/88] ip6mr: Fix potential Spectre v1 vulnerability Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 15/88] ipv4: " Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 16/88] ax25: fix a use-after-free in ax25_fillin_cb() Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 17/88] ibmveth: fix DMA unmap error in ibmveth_xmit_start error path Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 18/88] ieee802154: lowpan_header_create check must check daddr Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 19/88] ipv6: explicitly initialize udp6_addr in udp_sock_create6() Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 20/88] isdn: fix kernel-infoleak in capi_unlocked_ioctl Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 21/88] netrom: fix locking in nr_find_socket() Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 22/88] packet: validate address length Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 23/88] packet: validate address length if non-zero Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 24/88] sctp: initialize sin6_flowinfo for ipv6 addrs in sctp_inet6addr_event Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 25/88] vhost: make sure used idx is seen before log in vhost_add_used_n() Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 26/88] VSOCK: Send reset control packet when socket is partially bound Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 27/88] xen/netfront: tolerate frags with no data Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 28/88] gro_cell: add napi_disable in gro_cells_destroy Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 29/88] sock: Make sock->sk_stamp thread-safe Greg Kroah-Hartman
2019-01-11 14:07 ` [PATCH 4.4 30/88] ALSA: rme9652: Fix potential Spectre v1 vulnerability Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 31/88] ALSA: emu10k1: Fix potential Spectre v1 vulnerabilities Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 32/88] ALSA: pcm: Fix potential Spectre v1 vulnerability Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 33/88] ALSA: emux: Fix potential Spectre v1 vulnerabilities Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 34/88] ALSA: hda: add mute LED support for HP EliteBook 840 G4 Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 35/88] ALSA: hda/tegra: clear pending irq handlers Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 36/88] USB: serial: pl2303: add ids for Hewlett-Packard HP POS pole displays Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 37/88] USB: serial: option: add Fibocom NL678 series Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 38/88] usb: r8a66597: Fix a possible concurrency use-after-free bug in r8a66597_endpoint_disable() Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 39/88] Input: elan_i2c - add ACPI ID for touchpad in ASUS Aspire F5-573G Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 40/88] KVM: x86: Use jmp to invoke kvm_spurious_fault() from .fixup Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 41/88] perf pmu: Suppress potential format-truncation warning Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 42/88] ext4: fix possible use after free in ext4_quota_enable Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 43/88] ext4: missing unlock/put_page() in ext4_try_to_write_inline_data() Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 44/88] ext4: fix EXT4_IOC_GROUP_ADD ioctl Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 45/88] ext4: force inode writes when nfsd calls commit_metadata() Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 46/88] spi: bcm2835: Fix race on DMA termination Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 47/88] spi: bcm2835: Fix book-keeping of " Greg Kroah-Hartman
2019-01-11 14:08 ` Greg Kroah-Hartman [this message]
2019-01-11 14:08 ` [PATCH 4.4 49/88] cdc-acm: fix abnormal DATA RX issue for Mediatek Preloader Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 50/88] media: vivid: free bitmap_cap when updating std/timings/etc Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 51/88] MIPS: Ensure pmd_present() returns false after pmd_mknotpresent() Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 52/88] MIPS: Align kernel load address to 64KB Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 53/88] CIFS: Fix error mapping for SMB2_LOCK command which caused OFD lock problem Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 54/88] x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 55/88] spi: bcm2835: Unbreak the build of esoteric configs Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 56/88] powerpc: Fix COFF zImage booting on old powermacs Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 57/88] ARM: imx: update the cpu power up timing setting on i.mx6sx Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 58/88] Input: restore EV_ABS ABS_RESERVED Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 59/88] checkstack.pl: fix for aarch64 Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 60/88] xfrm: Fix bucket count reported to userspace Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 61/88] scsi: bnx2fc: Fix NULL dereference in error handling Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 62/88] Input: omap-keypad - fix idle configuration to not block SoC idle states Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 63/88] scsi: zfcp: fix posting too many status read buffers leading to adapter shutdown Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 64/88] fork: record start_time late Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 65/88] hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 66/88] mm, devm_memremap_pages: mark devm_memremap_pages() EXPORT_SYMBOL_GPL Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 67/88] mm, devm_memremap_pages: kill mapping "System RAM" support Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 68/88] sunrpc: fix cache_head leak due to queued request Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 69/88] sunrpc: use SVC_NET() in svcauth_gss_* functions Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 70/88] crypto: x86/chacha20 - avoid sleeping with preemption disabled Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 71/88] block: break discard submissions into the user defined size Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 72/88] block: dont deal with discard limit in blkdev_issue_discard() Greg Kroah-Hartman
2019-01-11 14:25   ` Mike Snitzer
2019-01-11 14:34     ` Mike Snitzer
2019-01-11 14:35     ` Greg Kroah-Hartman
2019-01-11 15:06       ` Mike Snitzer
2019-01-11 15:17         ` Greg Kroah-Hartman
2019-01-11 15:23           ` Mike Snitzer
2019-01-11 15:44             ` Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 73/88] ALSA: cs46xx: Potential NULL dereference in probe Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 74/88] ALSA: usb-audio: Avoid access before bLength check in build_audio_procunit() Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 75/88] ALSA: usb-audio: Fix an out-of-bound read in create_composite_quirks Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 76/88] dlm: fixed memory leaks after failed ls_remove_names allocation Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 77/88] dlm: possible memory leak on error path in create_lkb() Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 78/88] dlm: lost put_lkb on error path in receive_convert() and receive_unlock() Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 79/88] dlm: memory leaks on error path in dlm_user_request() Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 80/88] gfs2: Fix loop in gfs2_rbm_find Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 81/88] b43: Fix error in cordic routine Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 82/88] 9p/net: put a lower bound on msize Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 83/88] iommu/vt-d: Handle domain agaw being less than iommu agaw Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 84/88] ceph: dont update importing caps mseq when handing cap export Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 85/88] genwqe: Fix size check Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 86/88] intel_th: msu: Fix an off-by-one in attribute store Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 87/88] power: supply: olpc_battery: correct the temperature units Greg Kroah-Hartman
2019-01-11 14:08 ` [PATCH 4.4 88/88] vhost/vsock: fix uninitialized vhost_vsock->guest_cid Greg Kroah-Hartman
2019-01-11 14:33   ` Greg Kroah-Hartman
2019-01-11 21:46 ` [PATCH 4.4 00/88] 4.4.170-stable review shuah
2019-01-12  8:06 ` Naresh Kamboju
2019-01-12 14:57 ` Harsh Shandilya
2019-01-12 15:46   ` Greg Kroah-Hartman
2019-01-12 17:42 ` Guenter Roeck

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