Hi Borislav

Thank you for test the patch. It seems we can't use tasklet here due to mutex_lock.
And the spinlock may removed, I'm prepare to resend a different patch later.

Best Regards.
micky
On 04/20/2014 08:20 PM, Borislav Petkov wrote:
Hi,

On Wed, Apr 16, 2014 at 09:50:15AM +0800, micky wrote:
From: Micky Ching<micky_ch...@realsil.com.cn>

To avoid dead lock, we need make sure host->lock is always acquire
before pcr->lock. But in irq handler, we acquired pcr->lock in rtsx mfd
driver, and sd_isr_done_transfer() is called during pcr->lock already
acquired. Since in sd_isr_done_transfer() the only work we do is schdule
tasklet, the cmd_tasklet and data_tasklet never conflict, so it is safe
to remove spin_lock() here.

Signed-off-by: Micky Ching<micky_ch...@realsil.com.cn>
---
  drivers/mmc/host/rtsx_pci_sdmmc.c |    4 +---
  1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c 
b/drivers/mmc/host/rtsx_pci_sdmmc.c
index 453e1d4..40695e0 100644
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -108,12 +108,10 @@ static void sd_isr_done_transfer(struct platform_device 
*pdev)
  {
        struct realtek_pci_sdmmc *host = platform_get_drvdata(pdev);
-       spin_lock(&host->lock);
        if (host->cmd)
                tasklet_schedule(&host->cmd_tasklet);
-       if (host->data)
+       else if (host->data)
                tasklet_schedule(&host->data_tasklet);
-       spin_unlock(&host->lock);
  }
  static void sd_request_timeout(unsigned long host_addr)
--
Patch wouldn't apply against rc1, so I had to add it by hand, diff
below.

---
diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c 
b/drivers/mmc/host/rtsx_pci_sdmmc.c
index 5fb994f9a653..d1d65c0d8d2e 100644
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -109,12 +109,10 @@ static void sd_isr_done_transfer(struct platform_device 
*pdev)
  {
        struct realtek_pci_sdmmc *host = platform_get_drvdata(pdev);
- spin_lock(&host->lock);
        if (host->cmd)
                tasklet_schedule(&host->cmd_tasklet);
-       if (host->data)
+       else if (host->data)
                tasklet_schedule(&host->data_tasklet);
-       spin_unlock(&host->lock);
  }
static void sd_request_timeout(unsigned long host_addr)
--

Still needs more love:

[   95.112797] rtsx_pci_sdmmc rtsx_pci_sdmmc.0: sdmmc_get_cd: RTSX_BIPR = 
0x00010000
[   95.115700] mmc0: mmc_rescan_try_freq: trying to init card at 400000 Hz
[   95.118040] mmc0: clock 0Hz busmode 2 powermode 1 cs 0 Vdd 21 width 0 timing 0
[   95.122504] rtsx_pci_sdmmc rtsx_pci_sdmmc.0: sdmmc_switch_voltage: 
signal_voltage = 0
[   95.139469] mmc0: clock 400000Hz busmode 2 powermode 2 cs 0 Vdd 21 width 0 
timing 0
[   95.155461] mmc0: starting CMD52 arg 00000c00 flags 00000195
[   95.158617] rtsx_pci_sdmmc rtsx_pci_sdmmc.0: sd_send_cmd: SD/MMC CMD 52, arg 
= 0x00000c00
[   95.255497] rtsx_pci_sdmmc rtsx_pci_sdmmc.0: timeout for request
[   95.258412] ------------[ cut here ]------------
[   95.261163] WARNING: CPU: 0 PID: 3 at kernel/locking/mutex.c:698 
__mutex_unlock_slowpath+0x124/0x180()
[   95.264120] DEBUG_LOCKS_WARN_ON(in_interrupt())
[   95.264222] Modules linked in: cpufreq_stats cpufreq_conservative 
cpufreq_powersave cpufreq_userspace binfmt_misc uinput ipv6 vfat fat 
rtsx_pci_sdmmc mmc_core arc4 radeon rtl8192ce snd_hda_codec_conexant 
snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel rtl_pci rtlwifi 
snd_hda_controller snd_hda_codec mac80211 cfg80211 snd_hwdep snd_pcm 
drm_kms_helper pcspkr k10temp evdev snd_seq thermal thinkpad_acpi ehci_pci 
nvram rtsx_pci mfd_core snd_seq_device rtl8192c_common snd_timer ohci_pci 
ohci_hcd ehci_hcd snd battery ttm ac video button soundcore
[   95.264231] CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 3.15.0-rc1+ #1
[   95.264235] Hardware name: LENOVO 30515QG/30515QG, BIOS 8RET30WW (1.12 ) 
09/15/2011
[   95.264246]  0000000000000009 ffff8801198f3c50 ffffffff81522644 
ffff8801198f3c98
[   95.264254]  ffff8801198f3c88 ffffffff810701fc ffff8800c0ec1230 
ffff8800c28b5c30
[   95.264262]  ffff8800c0ec1000 ffff8800bea267b0 0000000000000000 
ffff8801198f3ce8
[   95.264264] Call Trace:
[   95.264277]  [<ffffffff81522644>] dump_stack+0x4e/0x7a
[   95.264288]  [<ffffffff810701fc>] warn_slowpath_common+0x8c/0xc0
[   95.264297]  [<ffffffff8107027c>] warn_slowpath_fmt+0x4c/0x50
[   95.264305]  [<ffffffff815294c4>] __mutex_unlock_slowpath+0x124/0x180
[   95.264311]  [<ffffffff8152952e>] mutex_unlock+0xe/0x10
[   95.264324]  [<ffffffffa0067119>] sd_finish_request+0xd9/0x1c0 
[rtsx_pci_sdmmc]
[   95.264332]  [<ffffffff810751a0>] tasklet_action+0x110/0x170
[   95.264338]  [<ffffffff810756ba>] __do_softirq+0x12a/0x320
[   95.264345]  [<ffffffff810758dd>] run_ksoftirqd+0x2d/0x50
[   95.264354]  [<ffffffff8109be75>] smpboot_thread_fn+0x175/0x2b0
[   95.264363]  [<ffffffff8109bd00>] ? SyS_setgroups+0x150/0x150
[   95.264372]  [<ffffffff8109497c>] kthread+0xfc/0x120
[   95.264382]  [<ffffffff81094880>] ? kthread_create_on_node+0x1f0/0x1f0
[   95.264390]  [<ffffffff8152bfec>] ret_from_fork+0x7c/0xb0
[   95.264398]  [<ffffffff81094880>] ? kthread_create_on_node+0x1f0/0x1f0
[   95.264403] ---[ end trace e7e46e1611dc934d ]---



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